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THE TEXTILE FIBRES. 



THEIR PHYSICAL, MICROSCOPICAL, 



CHEMICAL PROPERTIES. 



T. MERRITT MATTHEWS, Ph.D., 

■ ( 

Head of Chemical and Dyeing Department, 
Philadelphia Textile School. 



FIRST EDITION. 
FIRST THOUSAND. 



NEW YORK: 

JOHN WILEY & SONS. 

London : CHAPMAN & HALL, Limited. 

1904. 



\ fmo iJowes Rewiived 

OCi 1 1904 
Oostfliht Entry 

loUSS <^ XXo.No. 

970^1 

' COPY B 



X 






Copyright, 1904, 

BY 

J. MERRITT MATTHEWS. 



^ 




ROBERT DRUMMOND, PRINTER, NEW YORK 



PREFACE. 



The present book, it is hoped, will be of assistance to both 
the practical operator in textiles and the student on textile 
subjects. It has been the outgrowth of a number of years of 
experience in the teaching of textile chemistry, as well as prac- 
tical observation in the many mill problems which have come 
under the notice of the author. 

The textile fibres form the raw materials for many of our 
greatest industries, and hence it is of importance that the facts 
concerning them should be systematized into some form of 
scientific knowledge. The author has attempted, however, not 
to allow the purely scientific phase of the subject to overbalance 
the practical bearing of such knowledge on the every-day problems 
of industry. -* 

Heretofore, the literature on the textile fibres has been chiefly 
confined to a chapter or two in general treatises on dyeing or 
other textile subjects, or to specialized books such as Hohnel's 
work on the microscopy of the fibres. It has been the author's 
endeavor, in the present volume, to bring together, as far as 
possible, all of the material available for the study of the textile 
fibres. Such material is as yet incomplete, and rather poorly 
organized at its best; but it is hoped that this volume may prove 
a stimulus along the several lines of research which are available 
in this field. Unfortunately, the subject of the textile fibres 
has been lamentably neglected by chemists, although there is 
abundant indication that a fertile field of research is open to 
chemists in this direction, and such work would have not onlv 
a scientific value, but might also lead to great industrial worth. 
There is, as yet, relatively little known concerning the chemical 



iv PREFACE. 

constituents of the fibres, and the manner in which varying 
chemical conditions affect the composition and properties of 
these constituents. The action of various chemical agents on 
the fibre as an individual has been but very imperfectly studied. 
More work has been done in the microscopical field concerning 
the properties of the fibres; but even here, the knowledge is 
very incomplete and disjointed, and especial attention is drawn 
to the fact there is yet a large amount of work to be done in the 
microchemistry of the subject. 

The author has endeavored to emphasize throughout this 
Volume the importance of the study of the fibre as an individual, 
for in many cases it is misleading to assume that the behavior 
of the individual fibre is identical with that of a large mass of 
fibres in the form of yarn or cloth. In the latter case, the dif- 
ference in physical condition and the action of mechanical forces 
has an important influence. By going back to the study of the 
individual fibre as a basis, many explanations can be given which 
could not be discovered otherwise. 

It is hoped that this book may afford instruction both to 
the manufacturer and to the student; assisting the former in 
solving some of the many practical problems constantly occurring 
in the manufacture of textiles, and urging the latter on to an 
increased effort in the scientific development of the subject. 

J. Merritt Matthews. 

Philadelphia Textu-e School, 
August, 1904. 



CONTENTS. 



CHAPTER I. 

PAGE 

Classification of the Textile Fibres i 

I. Fibres Chiefly Used for Textiles. 2. Animal and Vegetable Fibres. 
3. Mineral and Artificial Fibres. 

CHAPTER n. 

Wool and Hair Fibres 5 

I. Wool and Hair. 2. Physiology and Structure of Wool. 

CHAPTER III 

The Chemical Nature and Properties of Wool and Hair Fibres . . 28 
I. Chemical Constitution. 2. Chemical Reactions. 3. Condition- 
ing of Wool. 

CHAPTER IV. 
Shoddy and Wool Substitutes 50 

CHAPTER V. 

Other Hair Fibres 55 

I. Fibres Related to Wool. 2. Mohair. 3. Cashmere. 4. Alpaca. 
5. Vicuna Wool. 6. Llama. 7. Camel's Hair. 8. Cow-hair. 9. Minor 
Hair Fibres; Horse -hair; Cat-hair, Rabbit-hair. 

CHAPTER VI. 

Silk; its Origin and Cultivation 68 

I. Mulberr>' Silk. 2. Wild Silks. 3. The Microscopical and Physi- 
cal Properties of Silk. 4. Silk-reeling. 

CHAPTER VII. 

Chemical Nature and Properties of Silk. . . 85 

I. Chemical Constitution. 2. Chemical Reactions. 3 Tussah Silk. 

V 



vi CONTENTS. 

CHAPTER VIII 

PAGE 

The Vegetable Fibres. . . ■ 97 

I. Basis of Vegetable Fibres. 2. Classification. 3. Physical Struc- 
ture and Properties. 

CHAPTER IX. 

Cotton no 

I. Origin and Growth. 2. Varieties of Cotton. 3. Vegetable Silks. 

CHAPTER X. 

The Physical Structure and Properties of Cotton 124 

I. Physical Structure. 2. Microscopical Properties. 3. Physical 
Properties. 

CHAPTER XI. 

Chemical Properties of Cotton; Cellulose 139 

I. Chemical Constitution. 2. Cellulose. 3. Chemical Reactions of 
Cotton. 

CHAPTER XII. 

Mercerized Cotton iS*^ 

I. Mercerizing. 2. Conditions of Mercerizing. 3. Properties of 
Mercerized Cotton. 

CHAPTER XIII. 
Artificial Silks; Lustra-cellulose 170 

CHAPTER XIV. 

Linen i77 

I. Preparation. 2. Chemical and Physical Properties. 

CHAPTER XV. 

Jute, Ramie, Hemp, and Minor Vegetable Fibres 184 

I. Jute. 2. Ramie or China-grass. 3. Hemp. 4. Sunn Hemp. 
5. Ambari or Gambo Hemp. 6. New Zealand Flax. 7. Manila Hemp. 
8. Sisal Hemp. 9. Aloe Fibre or Mauritius Hemp. 10. Pita Fibre. 
II. Pineapple Fibre or Silk-grass. 12. Coir Fibre. 



CONTENTS. vu 

CHAPTER XVI. 

PAGE 

Qualitative Analysis of the Textile Fibres 206 

I. Introductory. 2. Qualitative Tests. 3. Distinction between Cot- 
ton and Linen. 4. Distinction between New Zealand Flax, Jute, Hemp, 
and Linen. 5. Ligneous Matter. 6. Goodale's Table. 7. Systematic 
Analysis of Mixed Fibres. 8. Identification of Artificial Silks. 9. Dis- 
tinction between True Silk and Different Varieties of Wild Silk. 10. Mi- 
cro-analytical Tables. 

CHAPTER XVII. 

Quantitativ^e Analysis of the Textile Fibres 247 

I. Wool and Cotton Fabrics. 2. Wool and Silk. 3. Silk and Cotton. 
4. Wool, Cotton, and Silk. 5. Analysis of Weighting in Silk Fabrics. 



APPENDIX I. 
Microscopic Analysis of Fabrics 269 

APPENDIX II. 
Machine for Determining Strength of Fibres 272 

APPENDIX III. 

Bibliography of the Textile Fibres 275 

Index 279 



THE TEXTILE FIBRES. 



CHAPTER I. 

CLASSIFICATION OF THE TEXTILE FIBRES. 

1. Fibres Chiefly Used for Textiles. — In order to be service- 
able in a textile fabric, a fibre must possess sufficient length to 
be woven and a physical structure which will permit of several 
fibres being spun together, thereby yielding a continuous thread 
of considerable tensile strength and pliability. Although there 
are several fibres, such as spun glass, asbestos, various grasses, 
etc., which are used for the manufacture of textiles in peculiar 
and rare instances, yet the fibres which are employed to the 
greatest extent and which exhibit the most satisfactory qualities 
are wool, silk, cotton, and finen. All of these possess an organ- 
ized structure, and are the products of a natural growth in life 
processes. 

According to Georgevics, all textile fibres may be divided 
into four distinct classes; and though the same general arrange- 
ment is here preserved, the order has been somewhat changed 
so as to bring the most prominent ones first: (i) Animal fibres; 
(2) Vegetable fibres; (3) Mineral fibres; (4) Artificial fibres. 

2. Animal and Vegetable Fibres. ^According to their origin, 
we may divide the principal fibres into two general classes, those 
derived from animal and those derived from vegetable Hfe. The 
former includes wool and silk, and the latter cotton and linen. 
Animal fibres are essentially nitrogenous substances (protein 



2 THE TEXTILE FIBRES. 

matter), and in some cases contain sulphur. They may be solid 
filaments formed from a liquid secretion of certain caterpillars, 
spiders, or molluscs. Alkalies readily attack the animal fibres, 
causing them to be dissolved, but they withstand the action of 
mineral acids to a considerable degree. Contrary to the vege- 
table fibres, they are readily injured if exposed to elevated tem- 
peratures. Vegetable fibres consist of plant-cells, usually rather 
simple in structure and forming an integral part of the plant 
itself. They are capable of withstanding rather high tempera- 
tures, and are not weakened or disintegrated by the action of 
dilute alkalies. They consist essentially of cellulose, which may 
be in a very pure form, or be mixed with its various alteration 
products. In some cases the fibre consists of some cellulose 
derivative obtained by chemical means, such, for instance, as 
mercerized cotton. Concentrated alkalies produce alteration prod- 
ucts with the vegetable fibres. Free sulphuric or hydrochloric 
acid, even if only moderately strong, will quickly attack the 
fibre, disintegrating its organic structure and forming hydrolyzed 
products. Nitric acid, on the other hand, forms nitrocelluloses 
and various oxidation derivatives. 

3. Mineral and Artificial Fibres. — ^These two classes of fibres 
are of rare occurrence in the textile industry when compared 
with the extensive use of the preceding fibres. They find a lim- 
ited use, however, for certain purposes, and deserve to be con- 
sidered in a systematic study of the subject. The principal, 
and strictly speaking the only, mineral fibre is asbestos, which 
occurs in nature as the mineral of that name. It is a fibrous 
silicate of magnesium and calcium, though often containing iron 
and aluminium in its composition, especially in the dark-colored 
varieties. This mineral, though in the form of a hard rock, can 
be easily separated into slender white fibres, sometimes inclining 
towards a greenish color. The fibres of some varieties (Canadian) 
are curly, and afford the best material for spinning. In general, 
however, the fibres of asbestos are straight and glassy in structure, 
and are difficult to spin into a coherent thread. In order to 
enhance its spinning qualities it is mixed with a little cotton, the 
latter fibre being subsequently destroyed by heating the woven 



CLASSIFICATION OF THE TEXTILE FIBRES. 3 

fabric to incandescence. At the present time quite a variety of 
fabrics are manufactured from asbestos fibre, and the high quahty 
of many articles appearing on the market shows that the art of 
manipulating this substance has reached a high degree of perfec- 
tion. On account of its incombustible nature, and as it is a 
very poor conductor of heat, it is made into fabrics where these 
qualities are especially desired. Thus it is frequently manufac- 
tured into gloves and aprons, packing for steam- cylinders, the- 
atrical curtains and scenery, lamp-Avicks, etc. The latter use 
of asbestos was known to the ancients, who employed it for the 
wicks of the perpetual lamps in their temples. It is from this 
fact, indeed, that it received its name, the word "asbestos" mean- 
ing "unconsumed." It was also employed for napkins on 
account of its being readily cleansed, it only being necessary to 
heat the fabric in a flame to make it clean again. Asbestos, in 
general, is not dyed, and does not undergo any chemical proc- 
esses or modes of treatment. When it is desirable to dye it the 
various substantive dyes may be used with good effect, or the 
color may be applied by mordanting with albumen. 

The artificial fibres may be divided into two groups: (a) 
those of mineral origin and (b) those of animal or vegetable 
origin. In the first division may be classed such fibres as spun 
glass, metallic threads, and slag wool; in the second division 
may be put the various artificial silks, such as lustra-cellulose 
and gelatin silk. 

Fibres of spun glass are prepared by drawing out molten 
glass in the form of very fine threads ; colored glasses may be used 
to give rise to variously colored threads. Owing to its brittle 
nature and lack of elasticity, spun glass receives a very limited 
application, it being made into various ornamental objects, and 
sometimes into cravats. A variety of spun glass known as glass 
wool is used to some extent in the chemical laboratory as a filter- 
ing medium for liquids which would destroy ordinary filter-paper. 
Glass wool is curly, this property being given to it by drawing 
out the glass thread from two pieces of -glass of different degrees 
of hardness; and by unequal contraction on cooling, this double 
thread curls up. 



4 THE TEXTILE FIBRES. 

Various metals are at times drawn out into threads for use in 
decorative fabrics. Gold, silver, copper, and various alloys are 
used for this purpose. At the present time metallic threads are 
largely imitated by coating linen yarns w^ith a thin film of gold or 
silver. 

Slag wool is prepared by blowing steam through molten slag;, 
it can scarcely be called a textile fibre, but it is used in some 
degree as a packing material. 

Artificial silks are made either from cellulose derivatives or 
gelatin by forcing solutions of these through fine capillary tubes 
and coagulating the resulting threads and subsequently sub- 
jecting them to various processes of chemical treatment. As 
these belong more strictly to the class of true textile fibres, they 
will be given a more extensive consideration, in a further section, 
as being derivatives of cellulose. 



CHAPTER II. 

WOOL AND HAIR FIBRES. 

I. The woolly, hair-like covering of the sheep forms the most 
important and the most typical of the textile fibres which are 
obtained from the skin tissues of different beasts. The hairy 
coverings of a large number of animals are employed to a greater 
or lesser extent as raw materials for the manufacture of different 
textile products, but those of the various species of sheep make 
up the great bulk of the fibres which possess any considerable 
technical importance. Hairs, derived from whatever species of 
animals, have very much in common as to their general physical 
and chemical properties; they are also similar with respect to 
their physiological origin and growth. The hairs, however, of 
different animals, vary much in the detail of their special char- 
acteristics, and also with regard to their adaptability for use in 
the textile industry; and the wool of the sheep appears to exhibit 
in the highest degree those specific properties which make the 
most suitable textile fibre. These properties may be enumer- 
ated as being: (a) Sufficient length, strength, and elasticity, 
together with certain surface cohesion, to enable several fibres to 
be twisted or spun together so as to form a coherent and continu- 
ous thread or yam; (b) the power of absorbing coloring- matters 
from solution and becoming dyed thereby, and also the property 
of becoming decolorized or bleached when treated with suitable 
chemical agents; (c) in addition to these quahties, which they 
have in common with almost any textile fibre, wool fibres also 
possess the quahty of becoming felted or matted together, due 
to the pecuHar physical character of their surfaces. This property 

5 



6 THE TEXTILE FIBRES. 

is a most valuable one, as it adapts wool to a large number of 
uses to which other fibres are unsuitable. 

Silk is also a member of the general group of animal fibres, 
and though it possesses certain general chemical characteristics 
in common with wool and hair, yet it has an entirely different 
physiological origin, being a filament of animal tissue excreted 
by a certain species of caterpillar, and hence is totally different 
■from wool in its physical properties. Wool may be specifically 
designated as a variety of hair growing on certain species of mam- 
malia, such as sheep, goats, etc. The unmodified term " wool " 
has special reference to the product obtained from the different 
varieties of sheep. Cashmere, mohair, and alpaca are the products 
obtained from the thibet, angora, and llama goats, respectively. 
Fur is also a modified form of hair, but differs from wool in many 
of its physical properties, and is not adapted for use in the manu- 
facture of spun textiles. It is, however, largely employed for the 
making of hat felts. 

The wool-bearing animals all belong to the order Ruminan- 
tia, which includes those animals that chew their cud or rumi- 
nate. The principal members of this order are sheep, goats, and 
camels. The sheep belongs to the class Ovida, and occurs in a 
number of species which vary considerably in form and geographi- 
cal distribution, as well as in the character of the wool it pro- 
duces. Broadly considered, naturalists divide the sheep into three 
different classes: 

{a) Ovis arles, commonly known as the domestic sheep, and 
cultivated more or less in every country in the world. 

(b) Ovis musmon, occurring native in the European and 
African countries bordering on the Mediterranean Sea. 

(c) Ovis ammon, which includes the wild or mountain sheep 
(argali) to be found in Asia and America. The big-horn sheep 
of the Rocky Mountains belongs to this class.* 

* A more detailed classification than the above is given by Archer, who divides 
the sheep into thirty-two varieties: 

1. Spanish, or merino sheep (Ovis hispaniam). 

2. Common sheep (Ovis rusiicus). 
;^. ^Cretan sheep {Ovis strepsiceros). 



IVOOL AND HAIR FIBRES. 7 

The domestic sheep is the most important of these classes. 
It can hardly be said to be indigenous to any one country, for it 
appears to have been cultivated by the earliest peoples in history, 
and it has spread over the entire face of the globe with the gradual 
extension of civilization itself. Different conditions of climate 
and soil, of pasturage and cultivation, appear to exert a consider- 
able influence on the variety of the sheep and on the character of 
the w^ool it eventually produces. Variations are also produced 

4. Crimean sheep {Ovis longicandatus) . 

5. Hooniah, or black-faced sheep of Thibet. 

6. Cago, or tame sheep of Cabul {Ovis cagia). 

7. Nepal sheep {Ovis selingia). 
8 Curumbar, or Mysore sheep. 
9. Garar, or Indian sheep. 

10. Dukhun, or Deccan sheep. 

11. Morvant de la chine, or Chinese sheep. 

12. Shaymbliar, or Mysore sheep. 

13. Broad-tailed sheep {Ovis laticandatus) . 

14. Many-horned sheep {Ovis poly ceratus). 

15. Pucha, or Hindoostan dumba sheep. 

16. Tartary sheep. 

17. Javanese sheep. 

18. Barwall sheep {Ovis Barnal). 

19. Short-tailed sheep of northern Russia. 

20. Smooth-haired sheep {Ovis Ethiopia). 

21. African sheep {Ovis Grienensis). 

22. Guinea sheep {Ovis atnmon Guinensis). 

23. Zeylan sheep. 

24. Fezzan sheep. 

25. Congo sheep {Ovis aries congensis). 

26. Angola sheep {Ovis aries angolensis). 

27. Yenu, or goitred sheep {Ovis aries steatiniora). 

28. Madagascar sheep. 

29. Bearded sheep of west Africa. 

30. Morocco sheep {Ovis aries muncBdcB). 

31. West Indian sheep of Jamaica. 

32. Brazilian sheep. 

These represent the naturally occurring classes of sheep in the different coun- 
tries; of course, a large number have been emigrated and domesticated in other 
countries than those in which they had their origin, which has given rise to several 
sub-varieties. Then, too, new varieties have been formed by cross-breeding 
and intermixing, which has brought about a considerable variation in the type. 
The latter is also influenced very largely by climatic conditions, geographical en- 
vironment, and character of pasturage. 



8 THE TEXTILE FIBRES. 

by cross-breeding and intermixing, and the nature of the fibre has 
been much altered and improved by careful selection in breeding 
and genealogical development. 

Sheep in their natural condition produce two kinds of hair: 
the one giving a long, stiff fibre, which we will call " beard- hair "; 
and the other a shorter, softer, and more curly fibre, which we 
will designate as " wool-hair," or true wool. By domestication and 
proper cultivation the sheep can be made to produce the latter 
kind of hair almost exclusively, with but little or none of the hairy 
fibre. Herein the sheep differs essentially from the goat, as the 
latter will always produce both kinds of fibre, though the fineness 
and quality of its hair may be much improved by proper cultiva- 
tion. In addition to the above-mentioned varieties of hair, most 
sheep grow more or less of short, stiff hairs, or undergrowth; 
these have no value as textile fibres. It must be mentioned, how- 
ever, that the exact character of the wool on the individual sheep 
varies considerably with its position in the fleece; on the extrem- 
ities of the animal the wool becomes more hairy in nature, and 
near the feet the short undergrowth of stiff hair is alone to be 
found. The texture, length, and softness of the fibre also differ 
considerably in different portions of the fleece. Hence it becomes 
necessary, in order to obtain a homogeneous mixture of fibres 
with properties as constant as possible, to sort out the fibres of 
the fleece into different portions, which are put together into 
different grades of wool stock. This operation is termed wool- 
sorting and grading, and is an important step in the manufacture 
of wool. Different varieties of wool may require different sys- 
tems and degrees of sorting, but in general the fleece is roughly 
divided into nine sections, given as follows: 

(i) The shoulders and sides of the fleece give the finest and 
most even staples of fibre. 

(2) The lower part of the back yields a fibre of fairly good 
staple. 

(3) The loin and back give a shorter staple, and the fibre is 
not as strong. 

(4) The upper part of the legs give a staple of moderate 
length. The fibre on this part is frequently in the form of loose, 



^VOOL ^ND HAIR FIBRES. 9 

open locks and acquires a large amount of burrs by brushing 
against the spinose fruit of the plant; the presence of these burrs 
considerably lessens the commercial value of the wool. South 
American wool is especially liable to be heavily charged with 
burrs. 

(5) The upper part of the neck gives a rather irregular staple 
which is also very frequently filled with burrs. 

(6) The centre of the back gives a fine delicate staple similar 
to that from the loins. 

(7) The belly, together with the wool from the fore and hind 
legs yields a poor staple and a weak fibre. 

(8) The tail gives a short, coarse, and lustrous fibre, fre- 
quently containing a considerable amount of kemps. 

(9) The head, chest, and shins give a short, stiff, and straight 
fibre, opaque and dead white in color. 

The merino sheep, which yields what is considered to be the 
finest quality of wool, appears to have originated in Spain, and at 
one time was extensively cultivated by the Moors. The exporta- 
tion of merino sheep from Spain was long guarded against with 
great care, no one being allowed to take a live merino sheep out 
of the kingdom of Spain under penalty of death. Later, how- 
ever, this sheep was brought into various countries, being crossed 
with the different local breeds with very beneficial results. A 
German derivative of the Spanish merino known as the Saxony 
Electoral merino, gives perhaps the highest grade of fibre known 
in Europe. Australian sheep are mostly derived from merino 
and other high- class stock and yield a wool of the very highest 
quality. The merino has been cultivated and crossed with other 
breeds throughout the various parts of the United States, and the 
latter country is gradually becoming a large producer of middle 
grade wool. 

2. Physiology and Structure of Wool. — Wool, in common with 
all kinds of hair, is a growth originating in the skin or cuticle of 
the vertebrate animals, and is similar in its origin and general 
composition to the various other skin tissues to be found in ani- 
mals, such as horn, nails, feathers, etc. Wool is an organized 
structure growing from a root situated in the dermis or middle 



10 



THE TEXTILE FIBRES. 



layer of the skin; its ultimate physical elements being several 
series of animal cells of different forms and properties. Herein 
it differs essentially from silk, which is not composed of cells, but 
is a continuous and homogeneous tissue. The root of the wool 
fibre is termed the hair folHcle (Fig. i) ; it is a gland which secretes 



-pj: 




Fig. I. — Section of Hair Follicle. 
C, cuticle of skin; R, reta mucosum; PL, papillary layer; S, sebaceous glands; 
P, papilla; B, bulb of hair; H, hair; F, fibrous tissue; SH, transparent 
sheath. 

a lymph-like hquid, from which the hair is gradually developed 
by the process of growth. The hair folHcle also secretes an oil, 
which is supplied to the fibre during its growth, and serves the 
purpose of lubricating its several parts, giving it pliability and 
elasticity. In conjunction with the hair folhcle there also occur 
in the skin numerous sebaceous glands which secrete a fatty or 
waxy substance, commonly known as wool-fat. This substance 



IVOGL AND HAIR FIBRES. 



gradually exudes from the glands and coats the surface of the 
wool in rather considerable amount (Fig. 2). It affords a pro- 
tective coating to the fibre which serves to preserve the latter from 
mechanical injury during its growth, and also prevents the sev- 
eral fibres from becoming matted and felted together. In the 
preparation of wool for manufacture, this fatty covering has to be 
removed, the operation constituting the ordinary process of wool 
scouring. The oil, on the other hand, which is contained in the 
substance of the fibre itself, and is a true constituent of its sub- 




FiG. 2. — ^Wool Fibre in the Natural Grease (X350). 
The markings of the scales are scarcely apparent owing to the interstices being 
filled with greasy matter. 

stance, should not be removed, as its removal causes the fibre to 
lose much of its elasticity and resiliency. This oil amounts to 
about one per cent, of the total weight of the fibre, whereas the 
external fatty matter amounts on an average to about 30 per cent. 
Morphologically considered, the wool fibre consists of three 
distinct portions: (a) A cellular marrow, or medulla, which 
frequently contains more or less pigment matter to which the 
wool owes its color; (6) A layer of cellular fibrous substance or 
cortical tissue which gives the fibre its chief strength and elasticity; 
(c) An outer layer or epidermis of horn tissue, consisting of flat- 
tened cells, or scales, the ends of which generally overlap each 
other, and project outwards, causing the edge of the fibre to 
present a serrated appearance (Fig. 3). This scaly covering 



THE TEXTILE FIBRES. 



gives the fibre its quality of rigidity and resistance to crushing 
strain; it also causes the fibres to felt together on rubbing against 
one another by the interlocking of the projecting edges of the 
scales (Fig. 4). 

Any one of these three physical constituents may at times be 
lacking in a fibre. When the epidermal scales are absent, they 
have simply been rubbed off by friction; this condition is fre- 





FiG. 3. Fig. 4. 

Fig. 3. — Sections of Wool or Hair Fibre. 
a, cross-section of fibre; h, longitudinal section of fibre; A, epidermal layer of 
scales; B, cortical layer of fibrous cells; C, medullary layer of round cells. 
Fig. 4. — Diagram Showing Felting Action of Wool. 

quently to be found at the ends of long beard-hairs. The cortical 
layer of fibrous tissue is frequently but slightly developed, espe- 
cially in cases where the medulla is large : in some instances, indeed 
(as in the hair of the doe), the cortical layer appears to be totally 
absent in the broadest parts of the fibre. The medulla is very 



IVOOL AND HAIR FIBRES. 13 

frequently absent, or, at least, shows no difference in structure 
from the cells of the surrounding cortical layer; this occurs 
more especially in the wool- hairs, but is also to be found in beard- 
hairs. On the other hand, the medulla is more largely developed 
than the cortical layer, and becomes the principal part of the 
fibre, as in the beard-hairs of the doe. 

The microscopic appearance of wool is sufficiently character- 
istic to distinguish it from all other fibres. Under even moder- 
ately low power of magnification the scales on the surface of 
the fibre can be readily discerned, while neither silk nor the 
vegetable fibres present this appearance (Fig. 5). The scales 




Fig. 5. — \'arious Fibres. (Bowman.) 
A, Chinese wool; B, merino wool; C, cotton; D, silk; E, mohair. 

are more or less translucent in appearance, and permit of the 
under cortical layer being seen through them. The exact nature 
and structure and arrangement of the scales differ considerably 
with different varieties of wool. In fine merino wools, for in- 
stance, the individual scales are in the form of cylindrical cusps, 
one somewhat overlapping the other; that is to say, a single 
scale completely surrounds the entire fibre (Fig. 6). In some 
varieties of wool, on the other hand, two or more scales occur in 
the circumference of the fibre. In some cases the edges of the 
scales are smooth and straight (Fig. 7), and this appears to be 
especially characteristic of fine qualities of wool; the coarser 
species, on the other hand, possess scales having serrated wavy 



14 



THE TEXTILE FIBRES. 



edges. Usually such scales are much broader than they are long 
and are very thin (Fig. 8). The length of the free or projecting 




Fig. 6. — Typical Wool Fibres (X500). 
From a camera lucida micrograph, showing the irregular surface scales and the 
faint striations of the underlying fibrous layer of cortical tissue; the presence 
of the medullary cells is also plainly visible in one fibre. 




Fig. 7.— Wool Fibre (X350). 
With smooth, straight scales of a non-felting type. 

edge of the scale is also a very variable factor; in some wools the 
scale is free frorg the body of the fibre for about one-third of the 



WOOL /iND H^IR FIBRES. 15 

length of the former, and in consequence the scale protrudes to a 
considerable extent; such wool would be eminently suitable 
for the preparation of material which requires to be much felted 
(Fig. 9). In other wools, the free edge of the scale amounts to 
almost nothing, and the separate members fit down on one another 
closely, and are arranged like a series of plates. Wools of this 
class are more hair-like in texture, being stiffer and straighter. 




Fig. 8. Fig. 9. 

Fig. 8. — American Merino Wool. (Bowman.) 

Fig. 9. — Australian Botany Wool. (Bowman.) 

In fibres A and B irregularities in diameter may be noticed; but in fibres C and D 

the diameter is very uniform. 

and not capable of being readily felted (Fig. 10). The wool- 
hairs (the long, stiff fibres which have already been mentioned as 
occurring to a greater or lesser degree in nearly all wools, also 
known as beard-hairs) usually possess this structure. The felt- 
ing quality of wool is much increased by treatment with acid or 
alkaline solutions, or even boiling water, the effect being to open 
up the scales to a greater extent, so that they present a much 
larger free margin and consequently interlock more readily and 
firmly. Woolen yams, and woven materials made from such 
yarns, felt much more easily than worsted yarns, due to the fact 
that the fibres of the former lie in every direction and the inter- 
locking of the scales takes place more easily. 

In some varieties of wool fibre the scales have no free edge at 
all, but the sides fit tightly together with apparently no overlap- 



i6 



THE TEXTILE FIBRES. 



ping; in such fibres the surfaces of the scales are also more or 
less concave (Fig. ii). This structure only occurs with thick, 
coarse varieties of wool. Frequently at the ends of the wool 
fibre, where the natural point is still preserved (as in the case of 




Fig. 10. — ^Wool Fibre with Plate-like Scales. (Hohnel.) 

A, portion of fibre with isolated medullary cells at i, and smooth scales e fitting 

together like plates; B, portion of fibre showing medullary cylinder at m. 

lamb's wool from fleeces which have not been previously sheared), 
the scales are more or less rubbed off and the under cortical 
layer becomes exposed (Fig. 12); this appearance is quite charac- 
teristic of certain wools. In diseased fibres the epidermal scales 
may also be lacking in places, causing such fibres to be very 
weak at these points (Fig. 13). 

In most varieties of wools the scales of the epidermis may be 
readily observed even under rather low powers of magnification, 
while under high powers the individual scales may be seen over- 
lapping one another like shingles on a roof, and showing pointed, 



fVOOL /iND H/ilR FIBRES. 



17 





Fig. II. Fig. 12. 

Fig. II. — -Wool Fibre with Concave Scales. (Hohnel.) 
m, medullary cylinder consisting of several rows of cells; e, concave scales arranged 
in a plate-like manner. 

Fig. 12. — Showing Wool Fibre with Scales Rubbed Off. (Hohnel.) 
e, residue of epidermis; notice the coarse striations of the cortical layer under- 
neath the epidermis. 




Fig. 13. — Kempy Wool Fibres. (Bowman.) 

A, fibre with incomplete development of scales; B, fibre with scales undeveloped 

in certain parts only; C and D, diseased fibres. 



1 8 THE TEXTILE FIBRES. 

thickened protuberances at the edges. When the fibre becomes 
more hair-like in nature, such as mohair, alpaca, camel's hair, etc., 
it is more difficult to observe the individual scales, as these fuse 
together to a greater or lesser degree, until the true hair fibre is 
reached, which exhibits scarcely any markings of scales at all 
under ordinary conditions. By treatment with ammoniacal 
copper oxide, however, the interscalar matter is dissolved away, 
and even with true hair the scaly nature of the surface may be 
observed. Bowman gives the approximate comparative number 
of scales in different varieties of wool as follows: 

Wool. Scales, per inch. Diam. of Fibre (ins.). 

East Indian looo o . 00143 

Chinese 1200 0.00133 

Lincoln 1400 o . 00091 

Leicester 1450 0.00077 

Southdown : 1500 o . 00080 

Merino 2000 o . 00055 

Saxony 2200 o . 00050 

The epidermal layer of scales imparts to the wool fibre its 
characteristic quality of lustre. Since the lustre of any surface 
is due to the unbroken reflection of light from that surface, it may 
be readily understood that the smoother the surface of the fibre, 
the more lustrous it will appear. When the epidermal scales 
are irregular and uneven, and have projecting points and rough- 
ened edges, the surface of the fibre will naturally not be very 
smooth and uniform, and consequently will reflect light in only 
a broken and scattered manner. Such fibres will not have a 
high degree of lustre. On the other hand, when the scales are 
regular and uniform in their arrangement, and their edges are 
more or less segmented together to form a continuous surface, 
the fibre will be smooth and lustrous. As a rule, the coarser and 
straighter fibres are the more lustrous, as they approximate 
more closely to the structure of hair, which has a smooth surface. 
The lustre of the fibre being dependent on the polished surface 
of the scales is influenced largely by any condition which may 
affect the latter. Treatment with chemical agents, for instance, 
which will corrode the horny tissue of the scales, will seriously 
affect the lustre, as is evidenced by allowing alkaline solutions to 



^VOOL AND HAIR FIBRES. 19 

act on lustrous wool fibres. High temperatures (and especially 
dry heat) corrodes the epidermal scales and shrivels them up, 
causing the fibre to lose its lustre. In the various .mechanical 
processes through which the wool must pass in the course of its 
manufacture, the scales of the fibre suffer more or less injury, 
being torn apart, roughened, and loosened from the surface. In 
order to minimize the extent of this injury the wool is generally 
oiled, so that the surface of the fibres may be properly lubricated. 

The rigidity and pliability of the wool fibre is also largely 
conditioned by the nature of its epidermal scales. If these fit 
over one another loosely with considerable length of free edge, 
the libre will be very pliable and plastic, soft and yielding, also 
easily felted. Whereas, if the scales fit closely against one another 
and have little or no freedom of movement, the fibres will be stiff 
and resistant, and not easily twisted together nor felted. 

The cortical layer, or true fibrous portion of the fibre, forms 
the major constituent of wool. It consists principally of more or 
less elongated cells, and often presents a distinctly striated appear- 
ance, the striations being visible through the translucent layer 
of scales. The individual cells measure from 0.0025 in. to 0.0014 
in. in length, and from 0.00066 in. to 0.00050 in. in diameter, 
hence are elliptical in form. The cells may be disintegrated 
from one another by a careful treatment with caustic alkali. To 
this cortical tissue the fibre chiefly owes its tensile strength and 
elasticity. When the fibre is fine in staple, the cortical cells 
exhibit more or less unevenness in their growth and arrangement, 
with the result that the fibre is contracted on one side or the 
other, giving rise to the wavy or curled appearance of such wools. 
It is best, perhaps, to speak of the wool being *' wavy " rather than 
" curled," as the latter implies usually a spiral development which 
involves a twisting of the fibre, and in wool, as a rule, this does not 
occur. Coarse wools seldom exhibit this wavy structure, or only 
to a slight degree, the waves being long and irregular; some fine 
stapled wools, on the other hand, possess short and very regular 
waves. This property of the fibre adds much to its spinning 
qualities, and also to the resiliency of the yarn or fabric into 
which it is manufactured. Wool-hairs exhibit much less develop- 



20 THE TEXTILE FIBRES. 

ment of waves than the true wool fibres, and the more closely the 
anh-nal fibres approximate to the structure of ordinary hair, the 
less pronounced are the waves. Sheep's wool is more wavy 
than that derived from alhed species, such as the various goats, 
camel, etc. Mohair, for instar.ce, exhibits no wavy structure 
at all. The exact cause which determines the wavy quahty of 
wool is but ill-defined; there appears, however, to be some con- 
nection between the degree of curl, the diameter of the fibre, 
and the number of scales per inch. The following table, given 
by Bowman, shows the relation between the number of waves and 
the diameter of the fibre: 

Wool. Waves per inch. Diameter of Fibre (ins.). 

English merino 24-30 o . 00064 

Southdown 13-18 0.00078 

" II— 16 O.OOIOO 

Irish 7-11 0.00120 

Lincoln . 3-5 o . 00154 

Northumberland • 2-4 0.00172 

The waviness of the wool fibre may be temporarily removed by 
wetting with hot water and drying while in the stretched condition. 

In tensile strength and elasticity, the wool fibre varies within 
large limits, depending on the breed and quality of the sheep, 
and also the diameter of the fibre and the part of the fleece from 
which it was derived. The strength of wool, and of animal hairs 
in general, is due to the peculiar structure of the fibre. In the 
first place, the external sheath of horny tissue of flattened cells 
which take the form of scales, offers considerable resistance to 
crushing strains, and are also locked rather firmly together in 
the direction of the length of the fibre; this has a tendency to 
resist any diminution in the diameter of the fibre which would be 
felt when the latter is stretched. Then, too, the internal cortical 
cells of the fibre are so arranged as to present a very firm struc- 
ture, being firmly interlaced together, consequently, they offer 
considerable resistance to rupture. It has been noticed by a 
microscopical examination of a broken fibre that the cells them- 
selves are never ruptured, but only pulled apart from one an- 
other; this is evidence that the cell- wall is of a strong texture. 
The latter is probably formed of a continuous tissue which is less 



IVOOL /iND H/1IR FIBRES. 



21 



than 0.0002 inch in thickness, as under the highest powers of 
the microscope it exhibits no evidence of structural elements. 
Bowman gives the following table which records the average 
results of a number of experiments on the strength and elas- 
ticity of the wool fibre: 



Wool. 


Tensile 

Strength, 

grams. 


Elasticity, 
per cent. 


Diameter, 
ins. 


Human hair 


io6 
33 

31 
28 

5-9 
3-2 

2-5 

38 
9-7 


36.6 
28.4 

27-3 
27.0 
26.8 
33-5 
27-5 
29.9 
24.2 


0.00332 


Lincoln Wool 


Leicester 


0.00164 
. 00 1 49 
. 00099 
0.00052 
. 00034 


Northumberland 


Southdown wool 


Australian merino 


Saxonv merino 


Mohair 


Alpaca 


0.00053 





It is interesting to compare these figures of tensile strength for 
equal cross-sections of fibre. As the cross-section varies with the 
square of the diameter, by taking the ratio of the latter numbers 
and multiplying by the tensile strength, a figure is obtained which 
represents the tensile strength for equal diameters of fibres. In 
this manner the following table has been calculated, taking human 
hair as the standard for comparison, as it has the largest diameter : 

Human hair 100 

Lincoln wool 96.4 

Leicester 119 -9 

Northumberland 130 • 9 

Southdown wool 62 . 3 

Australian merino 122.8 

Saxony merino 224.6 

Mohair 136.2 

Alpaca 358.5 

Cotton (Egyptian) 201 . 8 

It will be noticed from this table that Saxony merino wool is 
by far the strongest of the different grades of wool. It is also 
interesting to note that cotton is considerably stronger than the 
majority of wools. 

The medulla, or marrow, of the wool fibre consists of round or 
slightly flattened cells, usually somewhat larger in section than 



22 THE TEXTILE FIBRES. 

those comprising the cortical l^-yer. The size of the medulla 
varies considerably in different varieties and grades of wool, and 
even shows large variations in fibres from the same fleece. At 
times it may occupy as much as one-quarter to one-third of the 
entire diameter of the fibre; and again, it may be reduced to 
almost a line, or even disappear completely. Wool-hairs exhibit 
the presence of a distinct medulla more frequently than the true 
wool fibres. The latter mostly show scarcely any inner structure 
at all, though at times there may be noticed isolated medullary 
markings, but usually the fibre is so transparent that it presents 
no markings at all. In camel's hair, however, the medullary 
portion shows up very distinctly, in some fibres appearing as a 
continuous dark band occurring about three-fourths of the width 
of the fibre, while in other fibres it shows a well-defined granular 
structure. In hairs of some other animals the medullary part 
exhibits a structure which is distinctly characteristic of the fibre; 
in the hair of the cat, for instance, the medullary cells appear in 
a reticulated form, and in the hair of the rabbit they occur as a 
series of laminae very regularly superposed on each other. The 
medullary cells frequently contain pigment matter, either con- 
tinuously or in isolated cells; and this may occur even in fibres 
usually classified as white wool. Sometimes the pigment per- 
meates not only the medulla, but also the cells of the cortical 
layer, in which case the fibre as a whole appears colored. To 
this class belong the variously colored wools, ranging from a 
light brown to almost a black. The hair of camels, goats, and 
other animals is also more or less colored, and to a much more 
general extent than sheep's wool. The medulla may consist of a 
single series of cells, or of several series arranged side by side; 
sometimes these cells occur in a discontinuous and rather irregu- 
lar manner, the intervening spaces of the medulla being filled 
with air. The function of the medulla is to provide the living 
fibre with an inner canal for the flow of juices whereby it receives 
nourishment for its growth. It also adds much to the porosity 
of the fibre, forming a capillary tube whereby the latter may suck 
up solutions of various kinds, such as dyestuffs, different salts, 
etc., allowing these to gradually permeate through the cortical 



IVOOL AND HAIR FIBRES. 23 

layer as well. The epidermal layer of scales is rather impervious 
to the transpiration of solutions, and only permits of their en- 
trance into the fibre at the joints of the scales, so it may be seen 
that the medulla of the fibre becomes an important adjunct in 
the chemical treatment of wool in the processes of mordanting, 
dyeing, and bleaching. It might also be noted, in this connec- 
tion, that the epidermal scales become but slightly, if at all, 
dyed when various coloring-matters are applied to the fibre, but 
remain clear and translucent. Hence it may be readily under- 
stood that if two samples of wool are dyed simultaneously, the 
one consisting of fibres having small and open scales, while the 
other has a thick and highly resistant epidermis, the resulting 
color on the two samples will have a different quality or tone, 
due to the influence on the latter of the uncolored and trans- 
lucent scales. In wools where this influence is very marked it is 
almost impossible to obtain rich and full shades of color, due to 
the transparency and lustre of the surface, which allows of con- 
siderable white light being refracted through the fibre along 
with the reflected color. This also explains the well-known fact 
that the longitudinal surface of the fibre in majiy cases presents 
a different tone of color than the cut ends, the latter usually being 
richer and deeper in tone; as may be noticed in cut-pile fabrics, 
such as occur in rugs, plushes, etc. In some cases the epidermal 
layer, instead of being highly translucent, is opaque and white; 
this is true of many varieties of coarse wool-hairs, and such fibres 
as cow-hair, etc. In such instances the dyed fibre will lack 
livehness of tone and appear rather dead and flat. The further 
discussion of this interesting subject must be dealt with in more 
detail in the study of shade matching. Attention is merely called 
to it at this point in order to emphasize more clearly the funda- 
mental cause of these differences in color phenomena as lying 
in the structure of the fibre itself. 

Frequently, through disease or other natural causes, the 
medulla of the wool fibre is imperfectly developed, in consequence 
of which the wool will not absorb solutions readily, and hence 
will not be dyed (or mordanted.) at all, or only slightly. These 
fibres, which are known as kemps, will occur through the mass 



24 THE TEXTILE FIBRES. 

of the wool as undyed streaks, and will give the yarn or fabric a 
speckled appearance. Not only may this condition, however, 
be brought about by natural causes, but it may at times be the 
result of artificial manipulation during manufacturing processes. 
There is a certain class of wool, for instance, known in trade as 
pulled wool; this is obtained from the pelts of slaughtered sheep, 
and is usually removed from the skin by the action of lime, the 
fibres being pulled out by the roots. In the process, the medulla 
becomes stopped up with solid insoluble particles of lime, which 
is also true of the end pores of the cortical layer and the joints of 
the scales. As a consequence, the fibre is very difficult to impreg- 
nate with solutions, and will remain more or less completely 
undyed. This non-porous character is also enhanced, perhaps, 
by the fact that the fibre does not possess a freshly cut end, but 
still retains the root, which is more or less rounded off and closed 
by the coagulation and hardening of the juices in the hair follicle. 

The medulla, as a rule, is more developed in beard- hairs than 
in wool-hairs, and more in coarse grades of wool than in the 
finer qualities. There also appears to be more or less relation 
between the breed of the wool and the morphological charac- 
teristics of the medullary cells, although this is a subject which 
as yet has been but little studied. At times the medullary cells 
exhibit but little differentiation from those of the cortical layers, 
and these two portions of the fibre become continuous in their 
appearance, that is to say, no line of demarcation can be drawn 
between the medulla and the surrounding cortical layer. 

In length, the wool fibre varies between large limits, not only in 
different sheep, but also in the same fleece. Generally speaking, 
the length may be taken as being between i and 8 ins. The 
diameter of the fibre is also very variable, even m the same 
fleece, but may be taken as averaging from 0.004 to 0.0018 in.* 
According to their length of staple, wool fibres are graded into 
two classes: tops and noils. The former includes the longer 
stapled fibres, which are combed and spun into worsted yarns, to 

* According to Hohnel, the diameter of sheep's wool varies from lo to loo // 
(the expression n = -j-irVo mm.) ; and according to Cramer, the thickness of the 
hairs from one and the same fleece may vary from 12 to 85 //. 



IVOOL /1ND H/ilR FIBRES. 25 

be manufactured into trouserings, dress-goods, and such fabrics 
as are not fulled to any extent in the finishing. The latter class 
consists of the short-stapled fibres, which are carded and spun into 
woolen yarns to be used for weft and all classes of goods which 
are fulled more or less in the finishing operations, where a felting 
together of the fibres is desired. On comparing worsted and 
woolen yarns, it will be noticed that the former are fairly even 
in diameter and the individual fibres lie more or less parallel 
to each other; whereas in woolen yarns the diameter is very 
uneven,, and the fibres lie in all manner of directions. 

The quality of wool obtained from sheep depends very largely 
on the breed, on climatic conditions, and nature of the pasturage 
on which the sheep feed. Australia appears to possess the cli- 
matic conditions best adapted for wool-growing.* With regard 
to the nature of the pasturage it has been found that grass from 
chalky soils gives rise to a coarse wool, whereas that from rich, 
loamy soils produces fine grades of wool.f As a rule, the sheep 

* Other conditions being equal, long droughty seasons in wool-growing dis- 
tricts will cause the fibre to be much shorter than otherwise. 

t Utah wools, for instance, are harsh and stairy compared to Wyoming wools. 
This is due to the alkali in the soil in Utah and the dryness of the climate. The 
alkali in the soil and the effect which it has upon the water which the sheep drink 
have a tendency to take the life out of the wool and weaken the staple. The more 
close and uniform the iibres lie, the better will be the combing qualities of the wool. 
The Utah wools in this respect are inferior to the Wyomings, Idahos, and Mon- 
tanas, especially the wools grown in southern Utah. In northern Utah the wools 
are longer than in southern Utah, but there are very few Utahs either north or 
south which are fit for combing. The heaviest shrinkage wools generally come 
from eastern Oregon and Nevada. The degree of shrinkage depends to a con- 
siderable extent on the season in which the wools were grown. A wet season 
and long-continued rains will wash much dirt and dust out of the wools, thus leav- 
ing them lighter. The lightest shrinkage wools come from Virginia and Ken- 
tucky and the Blue Grass region, where medium wools are grown, where the sheep 
are cleaner, the range better, and the country hilly, and where comparatively 
little sand and dirt work their way into the fleece. The shrinkage of washed 
fleeces ranges from 55% to 35%. Unwashed Indiana -wools shrink 38% to 43%. 
Missouris will shrink around 43% to 45%. Illinois, 45% to 47%. California 
wools shrink 55% to 72^, depending on the part from which they come. The 
heaviest shrinkage wools are in southern California, because of the presence of 
more sand and dirt, and inferiority of the range. Te.xas spring wools shrink 
anywhere from 64% to 72%, and the fall wools 58% to 64%. Territors' wools 
shrink from 55% up to 73%. Idahos on the medium order will not shrink over 



26 THE TEXTILE FIBRES. 

which yield the best quahties of wool give the poorest quality of 
mutton. 

Unhealthy conditions of the sheep almost always influence 
the fibre during that period of its growth. If the sheep, for 
example, is suffering from indigestion, cold, lack of proper nour- 
ishment, etc., the fleece during that time will develop tender 
fibres; when the sheep regains its normal condition of health, the 
fibre becomes strong again. Thus the fleece may have tender 
strata through it which will considerably affect the fibre and its 
uses. These tender spots, of course, render the wool unfit for 
combing purposes, and it must go into the "clothing" class, and 
will consequently sell for less money, other things being equal. 
It is no great injury to the wool, however, aside from spoiling it 
for combing, as the wool, after it has passed the tender spot, grows 
fully as well as before the sheep was ill. When sheep have been 
afflicted with scab, the latter shows itself in tender wool at the 
bottom of the fibre. The scab leaves a pus-like substance which 
adheres to the bottom of the fibres and dries there. Vermin on 
sheep have an influence on the wool; these creatures leave dis- 
colorations on the fibre which cannot be removed by scouring. 
The wool, being "off color," does not sell as well, and, moreover, 
the fibre is liable to be tender. 

As to the amount of wool to be obtained from each sheep, 
it may be said that the average yield is from 4 to 15 lbs., though 
in some South American varieties the fleece may weigh as high as 



55%- Wyoming wools on the fine and fine medium order shrink 65% to 72%. 
The Montanas shrink on the average 63% to 69% for fine and fine mediums, and 
57% to 60% for mediums. The shrinkage on Arizona wools will range from 
66% to 73%, but they will spin to finer counts than the Utah wools, and will scour 
out very white. In this latter respect the Wyoming wools are superior to any 
other grown west of the Mississippi River. The shortest wools grown in America 
are from California and Texas; they are used principally for felts and hats, though 
they can also be mixed in certain proportions with clothing wool. As the Terri- 
tory wools are grown mostly in dry climates, they will gain somewhat in weight 
on being shipped to the Atlantic seaboard and stored for a few months. Utah 
wools will gain about 1%, Montana wools about |%, and Wyoming wools about 
1%. The wools from Ohio and other eastern States will not gain anything; in 
fact, will sometimes show a slight shrinkage. {American Wool and Cotton Re- 
porter.') 



IVOOL AND HAIR FIBRES. 27 

30 to 40 lbs. With respect to the variation in fibres derived from 
different kinds of sheep, Bowman gives the following classifica- 
tion: 

(i) Those sheep the fibres of whose wool most nearly approach 
to a true hair, the epidermal scales being most horny and attached 
most firmly to the cortical structure. This class includes all the 
lustrous varieties of wool, besides alpaca and mohair. 

(2) Those where the epidermal scales, though more numerous 
than in the first class, are less horny in structure and less adherent 
to the cortical substance of the fibre. This class includes most 
of the middle-wooled sheep and half-breeds. 

(3) Those where the characteristics of true wool are most 
highly developed, such as suppleness of fibre and fineness of 
texture, the epidermal scales being attached to the cortical sub- 
stance through the smallest part of their length. This class 
includes all the finest grades of sheep, such as the merino and 
crosses with it. 



CHAPTER III. 

THE CHEMICAL NATURE AND PROPERTIES OF WOOL AND HAIR 

FIBRES. 

I. Chemical Constitution. — In its chemical constitution wool 
is closely allied to hair, horn, feathers, and other epidermal tissues. 
A distinction must be made between the fibre proper and the 
raw fibre as it comes from the fleece. In the latter condition it 
contains a large amount of dirt, grease, and dried-up sweat 
which have first to be removed by the scouring process before 
the pure fibre is obtained. Reserving these impurities for a 
further discussion which does not concern us at this point, and 
discussing only the fibre itself, it has been found to consist of 
five chemical elements; namely, carbon, hydrogen, oxygen, 
nitrogen, and sulphur. Nitrogen is an ingredient common to 
both wool and silk, but sulphur is distinctly characteristic of wool 
and hair fibres. To show the average amount of pure fibre to 
be obtained from raw fleece wool, the following analysis by Chev- 
reul of a merino wool is given: 

Per Cent. 
Earthy matter deposited by washing the wool in water. . . . 26.06 

Suint or yolk soluble in cold distilled water 32-74 

Neutral fats soluble in ether 8.57 

Earthy matters adhering to the fat i . 40 

Wool fibre 3 1 • 2^3 

100.00 

These figures are based on wool dried at 100° C; if corrected 

for air-dry wool containing 14 per cent, of moisture, this would 

give only about 27.5 per cent, of pure fibre. Of course, the 

amount of fibre will vary considerably in different qualities and 

samples of wools, but this figure may be taken as a fair average. 

The presence of nitrogen in wool is readily made evident by 

28 



^yOOL AND HAIR FIBRES. 29 

simply burning a small sample of the fibre, when the character- 
istic empyreumatic odor of nitrogenous animal matter will l)c 
observed. By heating wool in a small combustion test-tube it 
will be noticed that ammonia is among the gaseous products 
evolved, and can be tested for in the usual manner. The pres- 
ence of sulphur in wool can be shown by dissolving a sample of 
the fibre in a solution of sodium plumbite (obtained by dissolving 
lead oxide in sodium hydrate), when a brown coloration will be 
observed, due to the formation of lead sulphide. On adding 
hydrochloric acid to the solution and heating, the odor of sul- 
phuretted hydrogen will be distinctly noticed. The application 
of this test to show the presence of sulphur in wool is sufficient to 
discriminate chemically between that fibre and those consisting 
of silk or cotton, and also to detect wool in admixture with other 
fibres. The older methods of hair-dyeing were based on this 
same reaction, solutions of soluble lead salts, such as sugar of 
lead, being appHed to the hair, with the result that lead sulphide 
would be formed and cause a dark brown coloration. The use 
of such preparations, however, is dangerous, as they are liable to 
cause lead poisoning. 

The presence of sulphur in wool may at times be the cause of 
certain defects in the dyeing process. In neutral or alkaline 
baths, if lead is present, the color obtained on the fibre will be 
more or less affected by the lead sulphide formed on the wool, and 
serious stains may be the result. The presence of sulphuric 
acid, howe^'er, prevents this, and no staining of the fibre takes 
place. Stains are sometimes produced when wool is mordanted 
with stannous chloride, as in the dyeing of cochineal scarlets, due 
to the formation of stannous sulphide. Occasionally woolen 
printed goods exhibit brownish stains on the white or light- 
colored portions after being steamed. These may be due to slight 
traces of copper or lead being deposited on the cloth during its 
manipulation and passage through the machines, and these metals 
when the wool is steamed form dark-colored sulphides which cause 
the stains. By locally applying a weak solution of hydrogen 
peroxide such discoloration s may be removed without injury to 
the printed color. 



30 THE TEXTILE FIBRES. 

Chevrcul recognized the fact that in certain dyeing operations 
it was necessary to remove the sulphur from wool as far as possible 
in order to obtain the best results. He ac.compHshed this by 
steeping the wool in milk of lime and afterwards in a weak bath 
of hydrochloric acid, and finally washing. 

The amount of sulphur existing in wool does not appear to be 
a very constant factor, but varies in different samples of wool 
from 0.8 to 4 per cent. The manner in which the sulphur exists 
in the molecular structure of the fibre is by no means clear, as 
the majority of it is readily removed without any apparent struc- 
tural modification of the fibre itself. According to Chevreul, 
the amount of sulphur in wool was. reduced to 0.46 per cent, by 
several treatments with lime-water. Treatment with a concen- 
trated solution of caustic soda in such a manner as not to disinte- 
grate the fibre (see p. 40) will remove as much as 84.5 per cent, 
of the sulphur originally present in the wool. On a sample of 
wool containing 3.42 per cent, of sulphur, treatment in this man- 
ner left only 0.53 per cent, of sulphur in the fibre. This would 
appear to indicate that the sulphur is not a structural constituent 
of the wool fibre. The fact, however, that the sulphur present 
is not all removed by even such severe treatment as described 
would also serve to indicate that this element may exist in wool 
in two forms, the one an ultimate constituent of the fibre, and 
the other, and major part, as a more loosely combined compound. 
The fact that the amount of sulphur naturally present in wool is 
by no means constant would also tend to support this view; as 
would also the fact that the major portion of the sulphur is so 
readily spHt off to form metaUic sulphides. On dissolving wool 
in boihng caustic soda, it does not appear that all of the sulphur 
is converted into sodium sulphide, as only about 80 per cent, of 
it can be obtained as hydrogen sulphide when the caustic soda 
solution is treated with acid. Probably the remainder of the 
sulphur exists in the wool as a sulphonic acid, or some compound 
of a similar nature. 

In its chemiical nature wool appears to be a proteoid, known as 
keratin. As its constituents are not rigidly constant in their 
proportions, we cannot assign to wool a definite chemical for- 



PVOOL AND HAIR FIBRES. 31 

mula. On an average, its composition may be taken as 
follows : 

Per Cent. 

Carbon 50 

Hydrogen 7 

Oxygen 26-22 

Nitrogen 15-1 7 

Sulphur 2- 4 

Bowman gives the following analyses of four different grades of 
English wool : 



Constituent. 



Lincoln 
Wool. 



Irish 
Wool. 



Northum- 
berland 
Wool. 



South- 
down 
Wool. 



Carbon. . . 
Hydrogen, 
Nitrogen. 
Oxygen. . 
Sulphur. . 
Loss 



52- 

6. 

18. 

20. 



49- 
7- 

19. 

19. 
3- 



50.8 

7.2. 

18.5 

21 . 2 

2-3 



51-3 

6.9 

17.8 

20.2 

3-8 



These analyses were made of wool which had been purified by 
extraction with water, alcohol, and ether. 

The continued action of boiling water appears to decompose 
the wool fibre to a certain extent, as both ammonia and hydrogen 
sulphide may be detected in the gases evolved. 

By heating wool to a temperature of 130° C. with water under 
pressure, the fibre appears to become completely disorganized, 
and on dr}dng may be rubbed into a fme powder. At higher 
temperature the fibre is completely dissolved. Based on this fact, 
Knecht has proposed a method for the carbonization of wool in 
mixed woolen and silk goods, for the purpose of recovering the 
silk, as the latter is not materially affected by this treatment. 
The wool fibre as a whole does not appear to be a homogeneous 
chemical compound; instead of being a simple molecular body 
to which a definite formula might be given, it is doubtless com- 
posed of several chemically distinct substances. This is evi- 
denced by the fact that the proximate constituents of wool are 
by no means constant in their amount ; furthermore, certain of its 
constituents are in part removed by simply boiling the fibre in 
water without a structural disorganization taking place. The 



32 THE TEXTILE FIBRES. 

sulphur content is especially liable to fluctuation, and is the most 
readily removed of the chemical elements of which the fibre is 
composed ; in fact, so easily is some of the sulphur removed as such 
by various solvents, that it would seem to indicate that this con- 
stituent existed in wool either in the free condition or in a com- 
pound of exceedingly unstable character.. 

Schuetzenberger, by decomposing pure wool fibre by heating 
with a solution of barium hydrate at 170° C, obtained the fol- 
lowing decomposition products: 

Per Cent. 
Nitrogen (evolved as ammonia) 5 . 25 



Carbonic acid (separated as barium carbonate) 4 

Oxalic acid (separated as barium oxalate) 5 

Acetic acid (by distillation and titration) 3 

Pyrrol and volatile products i to i 

C 47 
Proximate composition of fixed residue, containing leu- 

cin, tyrosin, and other volatile products 



Williams has shown that by distilling wool with strong caustic 
potash a large amount of ammonia was obtained in the distillate, 
together with butylamin and amylamin. Dry distillation of 
wool yields an oil of a very disagreeable odor, probably consist- 
ing of various sulphuretted bases; also a considerable amount 
of pyrrol and hydrogen sulphide gas, together with a small amount 
of carbon disulphide, and traces of various oily bases. 

The fatty and mineral matters present on the raw wool fibre 
consist on the one hand of wool grease derived from the fatty 
glands surrounding the hair-follicle in the skin, and on the other 
hand, of dried-up perspiration from the sudorific glands in the 
skin. The wool grease is mostly to be found as the external 
coating on the fibre * which serves to protect it from mechanical 
injury and felting while in the growing fleece. "j" There is also a 

* The statement made in some text-books that raw wool when left in the 
greasy condition is not attacked by moths is erroneous. The personal experi- 
ence of the author has proved that raw wool is as liable to the depredations of 
insects as washed and scoured wool. 

t Cotted fleeces are those in which the fibres have grown in and amongst each 
other on the sheep's body so that they form a more or less perfect mat of wool. 
These mats are hard or soft according to the extent to which the matting process 



PVOOL AND HAIR FIBRES. 33 

small amount of oily mailer contained in the medullary intercellu- 
lar structure of the fibre which appears to have the function of 
acting as a lubricant for the inner portion of the fibre, thus pre- 
serving its pHability and elasticity. Wool grease does not appear 
to be a simple compound, but evidently consists of several oils 
and wax-like compounds. 

Its chief constituent is cholesterol, which appears to be one 
of the higher monatomic alcohols, and is not a glyceride. Analysis 
shows it to have the formula CogH^gOH. It is a solid wax-like 
substance which very readily emulsifies in water. Associated with 
cholesterol there is also an isomeric body called isochole sterol. 
Besides these solid waxes, wool grease also contains two fats 
which have been studied by Chevreul to some extent. These 
are described as follows: 

(a) Stearerin, a neutral solid fat, melting at 60° C. ; contains 
neither nitrogen nor sulphur; does not emulsify with boiling 
water, but emulsifies without saponification when boiled with 
two parts of caustic potash and water; it is soluble in 1000 parts 
of alcohol at 15.5° C. 

(&) Elairerin, a neutral fat melting at 15.5° C; also free 
from nitrogen and sulphur; it emulsifies with boiling water, 
and is saponified with caustic potash; it is soluble in 143 parts of 
alcohol at 15.5° C. 

The dried-up perspiration adhering to the raw wool fibre 
is also called suint. It consists principally of the potash salts 
of various fatty acids, and it is soluble in water, wherein it dift'ers 
from wool grease. On extraction with water, suint will yield a 
dry residue of about 140 to 180 lbs. for 1000 lbs." of raw wool. 



has been carried on. Cotted fleeces occur mostly in sheep which have been 
housed; they are seldom found in the territories where the sheep run on the range 
and are more exposed and hardy. Cotted fleeces indicate a low degree of vitality, 
and many are to be found in fleece wool from states east of the Mississippi River. 
They may be caused by sickness or a low state of the blood, or they may be found 
in an old sheep which is giving out or is run down, which contributes to the frowsy 
condition of the wool. Cotted fleeces are unfit for combing purposes, as they 
have to be torn apart, and frequently they are so dense and hard that the fibres 
can only be pulled apart by the use of special machinery. Badly cotted fleeces 
are used frequently for braid purposes. 



34 THE TEXTILE FIBRES. 

This on ignition will give 70 to 90 lbs. of potassium carbonate 
and 5 to 6 lbs. of potassium sulphate and chloride, so that the 
amount of potash salts to be derived from raw unwashed wool 
may be taken to be about 10 per cent, on the weight of the wool. 

Besides the mineral matter existing in the soluble suint, there 
is also a small amount of mineral matter which appears to form an 
essential constituent of the fibre itself. It is left as an ash when 
wool is ignited, and amounts on an average to about one per cent., 
the majority of which is soluble in water and consists of the alka- 
line sulphates. The following analysis by Bowman shows the 
typical composition of the ash of Lincoln wool: 

Per Cent. 

Potassium oxide 31 • i 

Sodium oxide 8.2 

Calcium oxide 16.9 

Aluminium oxide ) 

Ferric oxide j 

Silica 5.8 

Sulphuric anhydride 20.5 

Carbonic acid 4.2 

Phosphoric acid : trace 

Chlodn trace 

Sheep's wool is nearly always white in color, though sometimes 
it may occur in the natural colors of gray, brown, or black. The 
coloring-matter in wool appears to withstand the action of alkalies 
and acids, though it is not especially permanent toward light. It 
appears to be distributed in the fibre in quite a different manner 
from that of the artificially applied dyes. The natural coloring- 
matter appears to be contained particularly in the cells of the 
cortical layer and the marrow in a granular form, and to occur to 
a greater extent in the medullary than in the cortical cells. In 
fibres which are only slightly colored the walls of the cells are 
almost colorless; though when the fibre becomes very strongly 
colored the cell-walls also appear to be impregnated with the 
coloring-matter. In wools which have been dyed, however, the 
cell- walls are nearly always uniformly colored, in consequence of 
which the lumen of the fibre becomes less pronounced; whereas, 
with naturally colored wools, the lumen is usually rendered more 
distinct through the deposit of coloring-matter. 



IVOOL AND HAIR FIBRES. 35 

2. Chemical Reactions. — In its chemical reactions wool ap- 
pears to exhibit the characteristics both of an acid and a base, 
and no doubt it contains an amido acid in its composition. The 
presence of an amido group is evidenced by the formation of 
ammonia as one of the decomposition products of wool, also by 
the strong affinity of wool for the acid dyestuffs, or even of its 
ability to combine with acids in general. 

Schuetzenberger has shown that the products of the hydrolysis 
of wool by baryta- water arc analogous to those of albuminoids 
containing imido groups; the experiments of Prud'homme and 
FHck also indicate the presence of imido rather than amido 
groups in wool. The fact that wool absorbs nitrous acid, and 
combines with phenols, which is supposed to indicate the pres- 
ence of amido groups, may be explained by the formation of 
nitrosamines with the imido groups, which would also yield col- 
ored derivatives with phenols. 

The coefficient of acidity, which is a figure meaning the num- 
ber of milHgrams of caustic potash neutralized by one gram of 
substance, has been determined for wool, together with a number 
of other albuminoids, as follows: 

Wool S7-0 Albumin 20 . 9 

Silk 143 . o Gelatin 28 . 4 

Globulin loi . 5 

Although the amount of acid absorbed and neutralized by wool 
may be thus quantitatively determined, the amount of alkali 
absorbed cannot be so obtained, as wool, though it absorbs alka- 
lies, does not neutralize them. 

By treatment with concentrated solutions of caustic soda 
(80° Tw.) wool absorbs about 50 per cent, of its weight of sodium 
hydrate from solution. Nor can this alkali be totally removed 
from the wool by subsequent washing with water alone, but 
requires a treatment with acid for complete neutralization. Wool 
so treated exhibits a lessened affinity for basic d)-es, showing a 
probable neutraUzation to a greater or lesser extent of its acid 
component. 

The amido acid of keratin has received the name of lann- 
ginic acid, and has been prepared by dissolving purified wool 



36 THE TEXTILE FIBRES. 

in a strong solution of barium hydrate, precipitating the barium 
by means of carbon dioxide, and after fiUering, treating the 
liquid with lead acetate, whereby the lead salt is obtained. This 
is decomposed by means of hydrogen sulphide, and the lanuginic 
acid obtained, after evaporation, as a dirty-yellow substance. 
Its solution in water yields colored lakes with the acid and basic 
dyestuffs, and also with the various mordants. 

According to Knecht, lanuginic acid possesses the following 
properties: It is soluble in water, sparingly so in alcohol, and 
insoluble in ether. Its aqueous solution yields highly colored 
precipitates with the acid and basic dyestuffs; tannic acid and 
bichromate of potash also give precipitates. The following 
mordants in the presence of sodium acetate also give precipitates : 
alum, stannous chloride, copper sulphate, ferric chloride, ferrous 
sulphate, chrome alum, silver nitrate, and platinum chloride.. 
Lanuginic acid exhibits all the properties of a proteoid, and may 
therefore be classed among the albuminoids; it is soluble in 
water at all temperatures, and its solution is not coagulated.. 
With Millon's reagent and with the double compound of phos- 
phoric and tungstic acids, it shows the characteristic albuminoid 
reactions. Knecht recommends the use of a solution of wool in 
barium hydrate for the purpose of animalizing vegetable fibres. 
Cotton so treated is capable of being dyed with acid and basic 
dyestuffs. 

When heated to ioo° C, lanuginic acid becomes soft and 
plastic, and the majority of its colored lakes also melt at this 
temperature. It is completely soluble in water at all temper- 
atures and the solution is not coagulated by boihng. It also gives 
the characteristic albuminoid reactions with Millon's reagent^ 
and the double compound with phosphoric and tungstic acids. 
Knecht gives the following analysis of lanuginic acid: 

Per Cent. 
C 41 -61 



H 7 

N 10 

S 3 

O 31 



93-97 



IVOOL AND HAIR FIBRES. 37 

Though lanuginic acid contains a notable amount of sulphur in 
its composition, it is not blackened by treatment with sodium 
plumbite. 

When treated with dilute acids, the wool fibre does not appear 

to undergo any appreciable change; although, from the fact that 

acids are very readily absorbed by wool and very tenaciously held 

by it, there is reason to believe that some chemical combination 

takes place between the fibre and the acid. It can be shown, for 

example, that if wool be treated with dilute sulphuric acid, all of 

the acid cannot again be extracted by boiling in water until the 

wash waters are perfectly neutral; and wool thus prepared has 

the power of combining with the various acid colors without the 

necessity of adding any acid to the dye-bath. It is also true, that 

if wool which has been treated with sulphuric acid is boiled in 

water, ammonium sulphate is to be found in the solution, showing 

that some chemical action has probably taken place between the 

acid and some basic constituent of the wool fibre. Hydrochloric 

acid acts much in the same manner as sulphuric acid, although 

the amount permanently absorbed by the fibre is quite small, 

most of the acid being removed by boiling water. Chromic acid 

is also absorbed in like manner, and no doubt the usefulness of 

iDichromates as mordants for wool depends somewhat on the 

chemical combination between the fibre and the chromic acid. 

With nitric acid wool behaves somewhat differently, for unless 

the acid be very dilute and the temperature low, the fibre will 

assume a yellow color, which is probably due to the formation of 

xanthoproteic acid. Formerly this yellow color was supposed to 

be due to the formation of picric acid, but this view is erroneous. 

Nitric acid has a similar effect on the skin, the yellow stains which 

it produces being a subject of common experience. If the 

strength of the acid is below 4° Tw., the yellow coloration on 

wool is not very marked, and in this manner nitric acid has been 

largely employed as a stripping agent, especially for shoddies. 

Richards has shown that by the action of nitrous acid, wool is 
diazotized in a manner similar to an amido compound, and may 
be developed subsequently in an alkaline solution of a phenol, 
giving rise to quite a variety of shades. When wool is treated 



38 THE TEXTILE FIBRES. 

in the dark with an acid solution of sodium nitrite (6 per cent.) 
it quickly acquires a pale- yellow color, rapidly changing on expo- 
sure to light. Wool prepared in this manner is turned brown by 
boiling water, and caustic soda effects the same change, the color 
becoming yellow again on treatment with acids. Stannous chlo- 
ride in a warm solution discharges the brown color. Diazotizsd 
wool appears to have an increased attraction for basic dyes and a 
lessened affinity for the acid dyes. Exposure to light bleaches 
diazotized wool, which is then turned orange by alkalies, and 
not brown. The following colors may be obtained by treating 
diazotized wool with various phenols in alkaline solution : 

Phenol. Color. Reaction with H2SO4. 

Resorcin Orange Pale red 

Orcin Orange Pale red 

Pyrogallol Yellowish brown Orange 

Phloroglucin Bordeaux No change 

a-naphthol Red Black 

/?-naphthol Red Pale red 

When dyed in connection with metallic mordants, these phenol 
colors are fast to light, fulling, acids, and boiling water. Tin 
mordants give yellow and orange shades, aluminium orange, iron 
dark browns and olive browns, chromium and copper garnet. 
Wool treated with nitrous acid acquires a harsh feel and is non- 
hydroscopic. 

Its acid number is 169, and its iodin number 4.7, whereas 
untreated wool has the numbers 88 and 18.4 respectively. It 
also appears to contain less nitrogen than ordinary wool (Lidow, 
Chem. Centr., 1901, i, 703). 

Vignon (Compt. Rend., 1890, No. 17) has experimented on 
the amount of heat disengaged by treating wool with different 
acids and alkalies, with the following results, using 100 grams of 
unbleached wool: 

Reagent. Calories Liberated. 

Potassium hydrate (normal). . 24 . 50 

Sodium hydrate (normal) , 24 . 30 

Hydrochloric acid (normal) 20.05 

Sulphuric acid (normal) 20 . 90 

These figures are interesting in indicating the relative acidity 
and alkalinity of the wool fibre. 



IVOOL /iND HAIR FIBRES. 39 

In common with most other organic substances, wool is 
totally destroyed by the action of concentrated mineral acids. 

With organic acids, wool is usually reactive, readily absorbing 
oxalic, lactic, tartaric, acetic, etc., acids. Tannic acid, however, 
is an exception, and is not absorbed to any extent by the fibre. 
But if wool is treated in a boiling solution of tannic acid and the 
latter fixed in the fibre by a subsequent treatment in a solution 
of tartaric emetic (or other suitable metallic salt), it will be found 
that the fibre becomes altered in such manner that it no longer 
exhibits its normal affinity towards acid, substantive, and mor- 
dant dyes. Towards basic dyes, however, the affinity of the 
wool becomes considerably increased by reason of the presence of 
tannin. 

Although so resistant to the action of acids, on the other hand, 
wool is quite sensitive to alkalies; so much so, in fact, that a five 
per cent, solution of caustic soda at a boiling temperature will 
completely dissolve wool in five minutes. From this fact it is 
easy to understand why soaps, and scouring and fulling agents 
in general, should be free from appreciable amounts of caustic 
alkalies. The weaker alkaline salts, such as the carbonates, 
soaps, etc., are not so destructive in their action, and when em- 
ployed at moderate temperatures they are not regarded as dele- 
terious, and are largely used in scouring and fulling. With 
respect to the amount of caustic alkali necessary to decompose 
wool, Knecht found that on boiling wool for three hours with 
three per cent, (on the weight of the wool) of caustic soda the 
fibre was not disintegrated, but on increasing the amount to 
six per cent., complete disintegration took place and the wool was 
almost entirely dissolved. 

The action of concentrated solutions of caustic alkalies on 
wool is a rather peculiar one.* Solutions of caustic soda of a 
strength below 75° Tw. will rapidly disintegrate the fibre, but 
with solutions of 75°-! 00° Tw. the fibre is no longer disintegrated, 
but, on the other hand, increases from 25 to 35 per cent, in tensile 
strength, becomes quite white in appearance, and acquires a 

* Kertesz, Fdrber-Zeil., ix. 35-36; Buntrock, Fdrber-Zeil., ix. 69-71. 



40 THE TEXTILE FIBRES. 

high histre and a silky scroop. The maximum effect is obtained 
by using a caustic soda solution of 80° Tw. and keeping the tem- 
perature below 20° C* The duration of the treatment should not 
be more than five minutes. The addition of glycerin to the 
solution of caustic ~ soda renders the action of the alkali more 
effective. Wool treated in this manner may be said to be "mer- 
ceTrized," though the action of the caustic soda in this case is 
not quite analogous to that in the mercerization of cotton. From 
the decrease in the density of the caustic soda solutions employed, 
it has been shown that the wool absorbs a considerable amount 
of sodium hydrate from solution. Whether this is held by the 
wool in true chemical combination has not been ascertained. 
The treated wool contains but a small amount of sulphur com- 
pared with that present in the original fibre (see page 30) ; analy- 
sis, in fact, shows that only about 15 per cent, of the original sul- 
phur remains in the mercerized wool. The dyeing quahties of the 
latter are also different from the original fibre in that it absorbs 
more dyestuff from solution and hence yields heavier shades. 
Quantitative tests have shown that the increase in the absorption 
of dyestuff s is as follows: 

Increase, 
Class of Dyestuff. per cent. 

Basic 12.5 

Acid 20 . o 

Substantive 25.0 

Mordant 33-3 

Mercerized wool also shows an increased absorption with 
respect to solutions of various metallic salts. 

The exact nature of the action of caustic soda under the con- 
ditions given is rather difficult to satisfactorily explain. Through 
a microscopic examination of the treated fibres it appears that 
the individual scales on the surface of the wool are more or less 
fused together to a smooth surface, which would account for the 
great increase in lustre. The additional tensile strength is prob- 
ably accounted for by the same fact, the closer adhesions of the 
scales giving a greater rigidity to the fibre. The volatile alkalies, 

* Matthews, Journ. Soc. Chem. Ind., xxi. 685. 



H^OOL AND HAIR FIBRES. 4 1 

such as ammonia and ammonium carbonate, do not have any 
marked deleterious effect on wool, especially at low temperatures; 
hence these compounds form excellent scouring materials. The 
hydroxides of the alkaline earths, though less violent in their action 
than the fixed caustic alkahes, nevertheless decompose wool. 
Milk of lime, even in the cold, abstracts most of the sulphur, and 
also causes the fibre to become hard and brittle if the action is 
prolonged; the wool also loses its felting quality to a considerable 
extent. Barium hydroxide, as already noted, is used for the 
decomposition of wool in the preparation of lanuginic acid. 

Towards other chemical reagents wool is much more reactive 
than cotton, and either absorbs from solution or chemically com- 
bines with many substances. The fibre is quite readily oxidized 
when treated with strong oxidizing agents such as potassium 
permanganate or bichromate, becoming greatly deteriorated in 
its qualities. 

Towards chlorin wool acts in a peculiar manner; it is com- 
pletely decomposed by moist chlorin gas, but in weak solutions 
it absorbs a considerable amount of chlorin and is strangely 
altered in its properties.* It becomes harsh,"}" has a high lustre, 
and acquires a silk-like feel or "scroop," at the same time losing 
its felting properties, though its attraction for coloring-matters 
in general is largely increased. J 



* Bromin appears to have a similar action on wool. It is claimed to have 
the advantages over chlorin in that it does not turn the material yellow, and 
that in mixtures of dyed and undyed wool the former is not attacked. This 
latter statement is open to doubt. 

t According to a recent German patent, the harshness of chlorinated wool 
may be considerably lessened by working the material first in a solution of a salt 
such as citrate of zinc or acetate of iron, or of sodium stannate or aluminate; this 
is followed by a second bath of very dilute alkali, after which the goods are ex- 
posed to the air. The author, however, has not been able to obtain any satisfac- 
tory results on testing this process. 

X Chlored wool finds quite a number of applications in practice. The process 
is used, for instance, for the purpose of imparting a silk-like gloss to the fibre. 
Again, if yarns of chlored wool and ordinary wool are woven together in pattern, 
and the fabric afterwards fulled, since the chlored wool does not felt it will not 
shrink up like the remainder of the yarn, and in consequence the pattern will be 
brought out with very good effect; a great variety of novelties may be produced 
in this manner. Finally, the property of chlored wool to take up more dyestuff 



42 THE TEXTILE FIBRES. 

With neutral thetallic salts wool does not seem very reactive, 
as it does not absorb them appreciably from their solutions. 
With salts, however, which are acid in reaction and are capable 
of being easily dissociated, such as alum, ferrous sulphate, etc., 
the wool fibre possesses considerable attraction, especially when 
boiled in their solutions. 

With regard to coloring-matters, wool is the most reactive 
of all the textile fibres, combining directly with acid, basic, and 
most substantive dyestuffs, and yielding, as a rule, shades which 
are much faster than those obtained on other fibres. 

If wool is left in a warm place in a moist condition so that 
the fibre does not have free access to plenty of fresh air, it will 
soon develop a fungoid growth or mildew in spots. This causes 
the fibre to become tender and eventually rot. This fungoid 
growth will develop without any sizing ingredients or other for- 
eign matter being present on the fibre. It rapidly attacks the 
scales on the surface of the fibre, and then eats into the inner 
substance of the wool. Under the microscope (see Fig. 14) this 
fungoid growth appears as two forms: (a) Small elliptical cells 
which adhere to the surface of the fibre and spread out from it; 
they seem to colonize especially at the joints of the scales; (b) a 
tree-like growth consisting of several cells joined together and 
branching off from one another; these grow over the fibre as a 
kind of filmy integument, and do not appear to corrode the wool 

than ordinary wool, when dyed in the same bath, is also utilized; and fabrics with 
beautiful two-color effects may be easily obtained in this manner by weaving the 
chlored wool into designs with ordinary wool, and afterwards dyeing with suitable 
coloring-matters . 

The chloring of the woolen yarn is carried out in practice as follows: The 
material is well freed from all greasy matters by a prehminary scouring; this must 
be very thorough, otherwise good results will not be obtained, as the yarn is liable 
to finish up very uneven. A steeping in hydrochloric acid next takes place; the 
solution should be cold and have a density of i^° Tw. The wool should be left 
in this bath for twenty minutes. It is next passed into a solution of bleaching 
powder standing at 3° Tw., and worked for ten minutes; after which it is again 
treated with the solution of hydrochloric acid, and washed thoroughly. It is 
said that sodium hypochlorite is better to use than chloride of lime, and sulphuric 
acid is preferable to hydrochloric, showing less tendency to turn the material 
yellow. The yellow color due to the chlorin may be removed by treatment 
with sulphurous acid. 



^OOL AND HAIR FIBRES. 



43 



as rapidly as the first kind of cells. Mildew is especially apt to 
develop on woolen material which contains a small amount of 
alkali, the alkaline reaction probably being favorable to the 
growth of the fungus. 

Wool is more hygroscopic than any other fibre, but the amount 
of moisture it will contain will vary considerably according to 




Fig. 14. — Wool Fibres Attacked by Fungoid Growth (Mildew). 



the humidity and temperature of the surrounding atmosphere. 
Under average conditions, however, it will contain about 14-18 
per cent, of absorbed moisture. The hygroscopic quality of 
wool is a subject of considerable importance in the commercial 
handhng of this fibre, for the weight of any given lot of wool will 
vary within large limits in accordance with chmatic conditions; 
that is to say, the shipment of wool from one locahty to another 
of different humidity and temperature will cause a loss or gain 



44 ' THE TEXTILE FIBRES. 

in the apparent weight of the material. So important a factor 
has this become in the commercial relations between wool dealers, 
that conditioning houses for wool have been established in many- 
European centres for the purpose of carefully ascertaining the 
actual amount of fibre and moisture present in any given lot of wool, 
the true weight being based on a certain standard percentage of 
moisture, or so-called "regain." This percentage varies some- 
what with the character of the material and also the conditioning 
house, ranging from 19-16 per cent. The hygroscopic quality of 
wool also has an important bearing on the spinning and finishing 
processes for this fibre, it being necessary to maintain a definite 
and uniform condition of moisture in order that the best results 
be obtained in the spinning of yarns and the finishing of the 
woven fabric. The wool fibre also appears to possess a certain 
amount of water of hydration, which is no doubt chemically 
combined in some manner with the fibre itself; for it has been 
observed that wool heated above 100° C. becomes chemically 
altered through a loss of water at that temperature. This will 
no doubt explain the fact that air-dried wool is superior in quality 
to that dried by means of artificial heat, which usually signifies a 
rather elevated temperature. According to Persoz, the destruc- 
tive action of high temperatures on the wool fibre may be pre- 
vented by saturating the material with a 10 per cent, solution 
of glycerin, after which treatment the wool may be exposed to a 
temperature of 140° C. without being affected. The explanation 
of this action is no doubt to be found in the fact that glycerin 
holds water with considerable energy, and even at these elevated 
temperatures all of the moisture originally present in the wool 
is not driven out of the fibre. In order to economize time, it is 
sometimes necessary to dry wool rather quickly by the use of 
suitable machinery and high temperatures. Where a proper 
regulation of the temperature is possible, the wet wool may be 
subjected to quite a high degree of heat without injury, for the 
fibre itself does not become heated up, due to the rapid evapora- 
tion of the moisture. As the fibre becomes drier, however, it is 
important that the temperature fall, so that at the end of the 
operation, when the wool has become dried to its normal con- 



IVOOL AND HAIR FIBRES. 



45 



tent of moisture, the temperature should be that of the atmos- 
phere. 

Too much importance cannot be attached to the proper dry- 
ing of wool in all of its stages of manufacture, either in scouring, 
dyeing, washing, or finishing. If wool is overdried, that is, if 
the moisture in it is reduced to an amount much less than that 
which it would normally contain, inferior goods will always be the 
result, for the intrinsic good qualities of the fibre become greatly 
depreciated every time such a mistake is committed. 

The following table shows the percentage of moisture in air- 
dried wool and when exposed to an atmosphere saturated with 
moisture, as compared with the same values for other fibres: 



Fibre. 


Air-dry. 


Saturated. 


Fibre. 


Air-dry. 


Saturated. 


Wool 

Silk 


8-12 
lO-II 

6.66 
6.52 


30-40 

30 
21 
18.15 


Manila hemp. . . . 
Tute 


12.5 
6 

4.2-5.7 


40 

23-3 
13.9-24 


Cotton 


Flax 


Ramie 









3. Conditioning of "Wool. — In speaking of the hygroscopic 
quality of wool, it was mentioned that this fibre was capable of 
absorbing a considerable amount of moisture, and that this amount 
varied within rather large limits, depending upon the conditions 
of temperature and humidity of the air to which it may be exposed. 
It may be readily understood from these facts, that in the buying 
and selling of wool and woolen goods upon a basis of weight, the 
question as to how much moisture is present becomes of great 
practical importance in determining the money value of the 
operation. In England and on the continent of Europe, this 
fact has been recognized for some time, and there have been 
established at the various European wool centres official labora- 
tories wheref the percentage of moisture in raw wool or in manu- 
factured woolen material is carefully ascertained, and the sales 
are based on the actual amount of normal wool fibre contained in 
the lot examined. These official laboratories are called ' ' condi- 
tioning houses, ' ' and the process of determining the amount of 
moisture in the wool is termed "conditioning." In the condi- 
tioning of wool the operation is carried out as follows: Repre- 



46 THE TEXTILE FIBRES. 

sentative samples are taken from the lot under examination; 
these are mixed together, and three test samples of ^ to i lb. each 
are taken. The test sample, after being carefully weighed, is 
placed in the conditioning apparatus and dried to constant weight 
at a temperature of io5°-iio°C. (220° F.). This weight repre- 
sents the amount of dry wool fibre present in the sample, the loss 
in weight represents the amount of moisture the wool contained. 
The amount of normal wool is obtained by adding to the dry 
weight of the wool the amount of moisture supposed to be present 
in the air-dried material under normal conditions of humidity and 
temperature. The added amount is termed "regain," and is 
officially fixed by the conditioning house. This permissible 
percentage of regain varies with the form of the manufactured 
wool; the conditioning house at Bradford, England, for instance, 
has established the following figures: 

Per Cent. 

Wools 16 

Tops combed with oil 19 

Tops combed without oil 18^ 

Noils 14 

Worsted yarns 18^ 

The conditioning house at Roubaix, on the continent, allows 
the following percentages for regain on woolen materials : 

Per Cent. 

Wools 144 

Tops i8i 

Woolen yarns 17 

The method of calculating the amount of normal wool may 
be illustrated by the following example: A lot of 1000 lbs. of loose 
wool was submitted for conditioning; ten samples of i lb. each 
were taken from different parts of the lot; these were mixed 
together and three samples of 250 grams each were taken for 
testing. On drying to constant weight the three samples lost, 
respectively, (i) 18.25 per cent., (2) 18.30 per cent., (3) 18.22 per 
cent., making the loss 18.26 per cent. Hence in the entire lot 
of 1000 lbs. of wool there were 182.6 lbs. of moisture or looo— 
182.6=817.4 lbs. of dry wool. The permissible amount of 
regain in this case was 16 per cent.; hence the normal amount of 



fVOOL AND HAIR FIBRES. 



47 



wool would be (81 7.4 X ^ ) + 8i7.4=948.2 lbs. instead of 1000 

\ 100 / 

lbs. 

The apparatus to be employed for the conditioning test is 
usually one of such a construction as to be especially adapted 




Fig. 15. — Conditioning Apparatus. 

for the purpose. The form may differ somewhat in details with 
different makers, but a typical conditioning oven may be described 
as follows: 

The apparatus consists of an upright oven heated by a flame 
placed in the lower chamber. An even temperature is main- 
tained by so conducting the currents of heated air that they pass 
completely around the inner chamber or oven containing the 
sample to be tested. A thermometer projecting into the oven 



48 THE TEXTILE FIBRES. 

from above is employed for indicating the temperature, and this 
may be maintained at the desired point by a proper regulation 
of the supply of heat. The material to be conditioned, in what- 
ever form (as loose wool, yarn, etc.), is placed in a wire basket 
suspended from one arm of a balance fixed outside and above the 




Fig. 1 6. — Another Form of Conditioning Apparatus. 

oven; the weight of the basket and its contents is counterpoised 
by placing definite weights on a scale-pan suspended from the 
other arm of the balance. As the material diminishes in weight 
through the volatilization of its moisture, the loss is noticed from 
time to time by removing the necessary weights from the scale-pan 
in order to restore the equilibrium of the balance. When the 
weight becomes constant after heating at iic° C, the total loss is 
recorded, and this figure represents the amount of moisture 



IVOOL /1ND HAIR FIBRES. 49 

which was originally present in the material tested. The balance 
is usually enclosed in a suitable case in order to protect it from 
draughts of air whereby its sensibility would be impaired. 

Another form of conditioning apparatus of somewhat differ- 
ent shape is shown in Fig. i6. 



CHAPTER IV. 

SHODDY AND WOOL SUBSTITUTES. 

Besides the natural varieties of wool which find applications 
in the textile industries, we have a large quantity of regenerated 
wool employed as a textile fibre. This is obtained by tearing up 
woolen rags and waste, converting it back into the loose fibre and 
spinning it over again, either alone, or in admixture with varying 
proportions of pure fibre or fleece wool. This artificial wool, or 
wool substitute, as it is frequently called, is also obtained from 
rags and waste containing wool and cotton, or even silk; the vege- 
table fibre being destroyed by chemical treatment, leaving the 
animal fibre to be extracted and used again. On this account it 
is sometimes known as extract wool. The industry of converting 
regenerated fibre into yarns and fabrics has assumed of late 
enormous proportions, and nearly all cheap woolen goods contain 
a high percentage of these wool substitutes in their composition. 
Depending on its source of production, this regenerated wool will 
vary largely in its quality, and according to its origin and nature 
it is classed under several names, chief among which are the 
following : 

(a) Shoddy. Though this name is frequently applied to all 
manner of regenerated fibre, it is more specifically used to desig- 
nate that which is derived from all-wool rags or waste which have 
not been felted, also from knit goods. This yields the best qual- 
ity of fibre, the average length of which is about one inch. In 
many cases it is almost equal in quahty to a fair grade of fleece- 
wool, and is used in the production of many high-grade fabrics. 

(b) Mungo refers to the fibre obtained from woolen material 

50 



SHODDY AND IVOOL SUBSTITUTES. 5r 

which has been fulled or felted considerably; to disintegrate the 
rags the fibres must be torn apart, and consequently it yields 
fibres of shorter staple and less value than the preceding. 

(c) Extract wool is that obtained from mixed wool and cotton 
rags and waste, and has to undergo the process of carbonization 
whereby the vegetable fibre is destroyed.* It is sometimes called 
alpaca, and varies much in its length of staple and other qualities. 
Besides these well-known varieties of regenerated wool there are 
a number of others to be met with in commerce, such as Thibet 
wool, which is usually obtained from light-weight cloth clippings 
and waste. Cosmos fibre is a ver}^ low grade material, usually con- 
taining no wool at all, being made by converting flax, jute, and 
hemp fabrics back to the fibre. Even the short down obtained 
in the shearing of woolen cloths is used; it being employed as a 
filler. The process of using it is called " impregnating," and con- 
sists in fulling the short waste into the cloth on the under side. 

Woolen fibres consisting of shoddy, usually offer a very char- 
acteristic appearance under the microscope, sufficient, at least, to 
distinguish them from fibres of new wool. A sample of shoddy 
generally shows the presence of other fibres besides wool, and 
fibres of silk, linen, and cotton are frequently to be observed (Fig. 
17). Also, the colors of the different woolen fibres present is 
frequently quite varied, so that shoddy usually presents a multi- 
colored appearance under the microscope. A very striking 
appearance, also, is the simultaneous occurrence of dyed and 
undyed fibres; the diameters of the fibres will also vary between 
large limits, the variation in this respect being much more than 
with fresh wool. Some samples of shoddy will also show a large 
number of torn and broken fibres; and usually, the external 
scales are rougher and more prominent. 

It must be borne in mind, however, that pure wool may also 



* This process is generally carried out by steeping the rags in a solution of 
sulphuric acid (6° Tw.) at 140° to 180° F., and then drying; whereupon the vege- 
table fibres are decomposed and are easily dusted out by willowing, whereas 
the wool fibres are scarcely affected. The excess of acid is then removed by 
treatment with soda-ash and washing. The fibres obtained are sometimes over 
one inch in length. 



52 



THE TEXTILE FIBRES. 



show the presence of small quantities of vegetable fibres at times. 
These often arise from the occurrence of burrs (bristly and barbed 
seeds of various plants) in the original fleece. South American 
wools are especially liable to contain such burrs; in many cases 
these are incompletely removed, and may ultimately appear even 
in the woven cloth. This frequently explains the existence of 
short fibres or vascular bundles of vegetable matter in cloth. 
Isolated fibres of woody tissue and cotton may also accidentally 




Fig. 17. — Typical Appearance of Shoddy Fibres (X 250). 
Showing fibres of various characters and colors. 

creep in through a variety of causes. According to Hohnel, 
samples of pure wool may easily contain as much as ^ per cent, 
of vegetable fibre. The latter authority also states that the vege- 
table fibres of shoddy, as a rule, are removed by carbonizing; 
hence the absence of cotton, linen, etc., must not be taken as a 
criterion to distinguish between pure wool and shoddy. When, 
however, cotton (always dyed) or cosmos fibre occurs in at least 
a quantity of one per cent., this may be taken as a direct indica- 
tion of the presence of shoddy, as it would scarcely ever happen 
that pure wool is adulterated with cotton; this only happens by 
admixture with shoddy-wool. Undyed cotton, unless present in 
considerable amount, cannot be considered as a suspicious com- 
ponent. 

The determination of the length of staple is also a rather unre- 



SHODDY AND IVOOL SUBSTITUTES. SZ 

liable indication as to the presence of shoddy, for there are vari- 
eties of shoddy-wools which are longer in staple than many fleece- 
wools; and also woven goods, though composed entirely of 
fleece-wool, may show the presence of a large number of short 
fibres caused by the shearing of the surface of the cloth, and also 
brought about by tearing of the fibres in heavy pulling. 

Where woolen cloth has been impregnated or filled with 
short fibres obtained from clippings, such may usually be recog- 
nized by teasing the sample out with a stiff bristle-brush. Good 
cloth should not yield over \ per cent, of clipped fibres from both 
sides. When the amount of such fibres is at all considerable, 
they may be used as serviceable material to test microscopically 
for shoddy, as they are most likely to be made up of this character 
of wool. 

Fine fleece-wools hardly ever show the absence of epidermal 
scales (though this is frequently the case with coarse wools); 
hence if examples of such fine wools are found showing a lack of 
epidermis, it may usually be taken as an indication of shoddy. 

Hohnel, however, calls attention to the fact that the following 
conditions previous to the manufacturing process itself have con- 
siderable influence on the good structure and integrity of the 
wool fibre : badly cut staple, lack of attention in raising the sheep, 
poor pasturage, sickness of the animal, the action of urine, snow, 
rain, dust, etc., packing the wool in a moist condition, rapid 
and frequent changes of moisture and temperature, the use of too 
hot or too alkaline baths in scouring, scouring with bad deter- 
gents, etc. These influences may lead to the partial removal of 
the epidermis, and to the softening and breaking of the ends of 
the fibre. There must also be considered the influence of wil- 
lowing, carding, combing, spinning, weaving, gigging, fulhng, 
acidifying, washing, shearing, pressing, etc., from which it is 
easy to understand why even fleece- wool may show the entire 
absence of epidermis. Hohnel also criticises other alleged char- 
acteristics of shoddy, such as torn places in the fibre, uneven- 
ness in diameter, etc., claiming that these can hardly be taken 
as an indication of shoddy, because such marks are often regu- 
larly present in many fleece-wools. IS'Iost samples of shoddy, in 



54 THE TEXTILE FIBRES. 

fact, show scarcely any structural differences from ordinary 
fleece- wool. The ends of shoddy fibres, however, usually present 
a torn appearance; at least there is a great predominance of such 
fibres in shoddy, whereas in fleece-wool this appearance is seldom 
to be observed, the end of the fibre being cut off sharply. The 
appearance of the torn fibres may be easily observed under the 
microscope; the epidermis being entirely torn away, as well as 
the marrow which is sometimes present, while the fibrous cortical 
layer is frayed out like the end of a brush. This appearance can 
usually be rendered more distinct by previously soaking the fibres 
in hydrochloric acid. Sheared fibres are recognized by being 
very short and by having both ends sharply cut off. 

The color of the fibres is also a characteristic appearance of 
shoddy, as the majority of shoddy is made up of variously colored 
wools. It is of rare occurrence that rag- shoddy possesses a single 
uniform color. Hence if a sample of yarn, possessing a single 
average color, on examination reveals the presence of^ variously 
colored fibres, it is ahnost a positive indication of shoddy. In 
this connection it must not be forgotten, however, that fre- 
quently differently colored wools are mixed together previous to 
spinning, to make so-called "mixes." As a rule, however, only 
two to three colors are used together; therefore a purposely mixed 
yarn of this description is not likely to be confounded with a 
shoddy yarn where individual fibres of a large number of colors 
are nearly always shown. 



CHAPTER V. 

OTHER HAIR FIBRES. 

1. Besides the fibre obtained from the domestic sheep, there 
are large quantities of hair fibres employed in the textile indus- 
tries and obtained from related species of animals, such as goats, 
camels, etc. As these are all more or less utilized in conjunction 
with wool itself, and are subjected to similar operations in manu- 
facturing, it will not be out of place to consider them at this point. 
The chief among these related fibres are mohair, cashmere, 
alpaca, cow-hair, and camel's hair. 

2. Mohair. — This fibre is obtained from the Angora goat, an 
animal which appears to be indigenous to western Asia, being 
largely cultivated in Turkey and neighboring provinces. The 
fleece is composed of very long fibres, fine in staple, and with little 
or no curl. The fibre is characterized by a high silky lustre. 
Mohair is now grown to a considerable extent in the Western 
States, principally Oregon, California, and Texas, the goats 
having originally been imported from Turkey; there is also a 
large quantity of mohair grown in Cape Colony. The principal 
mohair clips (1902) are as follows: 

Turkey 8,500,000 lbs. 

Cape Colony 7,500,000 " 

United States 1,250,000 " 

The principal use of mohair is for the manufacture of plushes, 
braids, fancy dress fabrics, felt hats, and linings. The charac- 
ter of fabric in which it may be employed is rather limited on 
account of the harsh wiry nature of the mohair fibre, and the 
fact that it will not fek to any degree. Domestic mohair (Ameri- 

55 



S6 THE TEXTILE FIBRES. 

can) has only about two-thirds of the value of the foreign fibre; 
mohair in general has quite a large amount of kempy fibre (which 
will not dye), but the domestic variety contains about 15 per cent, 
more kemp than the foreign, hence the lower value of the former. 
Another reason for this lessened value is that foreign mohair always 
represents a full year's growth (the fibres being 9 to 12 ins. in 
length), whereas a great deal of domestic mohair is shorn twice 
a year. This is especially true of that grown in Texas : the hair 
commences to fall off the goats in that district if allowed to grow 
for the full year. In judging of the quality of mohair, the length 
and lustre are of more value than the fineness of staple. The finest 
grades of domestic mohair come from Texas, that from Oregon 
and California being larger and coarser. In Oregon the fleece 
is grown for a full year, and consequently the fibre is very long. 
The average weight of the fleece from Oregon goats is 4 lbs., while 
in Texas it is only 2^ lbs. Foreign mohair varies much in quahty, 
depending upon the district in which it is grown; as a rule, the 
finer varieties are shorter in staple, the finest being about 9 ins. in 
length. Foreign mohair can be spun to as. high a count as 6o's, 
whereas the finest quality of domestic mohair can only be spun 
to as high as 40's. The coarsest varieties of mohair are used in 
carpets, low-grade woolen fabrics, and blankets. 

Microscopically, the mohair fibre is possessed of the following 
characteristics: The average length is about 18 cm., and the 
diameter about 40 to 50 n, and very uniform throughout the entire 
length. The epidermal scales can only be observed with diffi- 
culty, as they are very thin and flat, though regular in outline. 
They are also very broad, a single scale frequently surrounding the 
entire fibre; the edge of the scale is usually finely serrated. The 
best grades of fibres show no medulla, but there are usually to 
be found (especially in domestic mohair) coarse, thick fibres pos- 
sessing a broad medullary cyhnder, thus resembling the structure 
of ordinary goat-hair, from which, however, they are to be dis- 
tinguished by being more slender and more uniform in their diam- 
eter. Longitudinally, the fibre exhibits coarse, fibrous striations, 
approximating the appearance of broad and regularly occurring 
fissures (see Fig. 18). Due to the fact that the surface scales 



OTHER. HAIR FIBRES. 



57 



lie very flat and do not project over one another, the edge of the 
fibre is very smooth, showing scarcely any serrations at all, which 
accounts for its utter lack of felting quahties. The outer end of 
the fibre is either slightly swollen or blunt, but never pointed. 
When viewed under polarized light the fibres occasionally show 
the presence of a medullary canal, which appears as a hollow 
space, giving an illumination somewhat resembling that of a 




Fig. i8. — Mohair Fibres (X350). 
Showing fine, smooth scales and straight edges. 

bast fibre, and covering from one-fourth to one-half of the 
diameter. 

3. Cashmere is remarkable for its softness and is much used 
in the woolen industry for the production of fabrics requiring 
a soft nap. Cashmere is the fibre employed in the manufacture 
of the famous Indian shawls. There are two qualities of cash- 
mere wool, the one consisting of the fine, soft down-hairs, and 
the other of long, coarser beard-hairs. The former are i^ to 3^ 
ins. in length and 13 ,« in diameter, while the latter are 3^ to 4^ ins. 
in length by 60 to 90 ix in diameter. The down- hairs show 
visible scales but no definite medulla, whereas the beard-hairs 
possess a well-developed medulla. The cortical layer is coarsely 
striated, and shows characteristic fissures. At the point of the 



58 



THE TEXTILE FIBRES. 



fibre the epidermal scales are either entirely absent, or are so 
thin as to be scarcely visible. The fibre is very cylindrical; 
the scales have their free edge finely serrated, and the edge of 
the fibre also presents the same appearance. 

Besides mohair and cashmere, the hair of the ordinary goat 
is also used at times. It has the following characteristics (Hohnel) : 
It is white, yellow, brown, or black in color, and generally 4 to 
10 cm. long. It consists almost entirely of wool-hairs, which, 
like pulled wool, nearly always show the hair root. The average 
hair exhibits the following structure (see Fig. 19): At the base 





Fig. 19. — a, Cow-hair; h, Goat-hair. (Hohnel.) 
q, characteristic fissures in marrow; m, marrow or medulla filled with air; 
/, fibrous fissures; e, tile-shaped scales. 

it is about 80 to 90 ix thick; the root is about | mm. long; the 
marrow is just visible at the root, then rapidly increases in thick- 
ness, so that a few millimeters from the base it is 50 p. thick, 
v/here the thickness of the hair amounts to 80 to 90 ,«. The 
cortical layer from this point on forms a very thin cylinder. The 
cross- section is round; the epidermis consists of broad scales 
about 15 /I long, the forward edges of which are scarcely thickened, 



OTHER HAIR FIBRES. 59 

but appear as if terminated by a sharp line; furthermore they 
are not serrated. The medullary cells are thick-walled, narrow, 
and flattened. Towards the end the hair is very brittle and 
easily broken. Colored goat-hair shows the presence of pigment 
matter in all of its tissues; in such fibres the marrow appears 
black. 

4. Alpaca, and its varieties Vicuna and Llama, have the dis- 
advantage of being mostly colored from brown to black. 
Though largely used in South America for the production of 
various fabrics, they do not find much application in the general 
textile industry. There is another product in trade which goes 
by the name of vicuna (French vicogne), which must not be 
confused with the true South American fibre, it being simply 
a trade-name for a mixture of cotton and wool. The name 
alpaca is also given to a variety of wool substitute. The South 
American wools often give rise to wool-sorter's disease to those 
handling them. This disease is anthrax and is caused by the 
presence of a certain microbe in the fibre. Wool-sorter's disease 
is caused by Bacillus anthracis, which may enter the system 
either by the skin (through the medium of an abrasion or cut) 
or by the internal organs, being introduced with the food. In 
the former case it gives rise to pustules, which become painful 
and cause excessive perspiration, fever, delirium, and sundry 
disorders. In the latter case it gives rise to the most serious 
results, leading to blood-poisoning and inflammation of the lungs, 
which often' prove speedily fatal. 

True alpaca is obtained from the cultivated South American 
goat, Auchenia paco. It occurs in all varieties of colors from 
white, through brown, to black. The reddish-brown and not 
the white variety, however, is the most valuable. Like other 
goat-hairs, alpaca consists of two varieties of fibres, a soft :,'col- 
hair and a stiff beard-hair. The wool-hairs of the reddish -^r^wn 
variety are from 10 to 20 cm. in length, and from 12 to '^5 ,a in 
diameter (see Fig. 20). The fibre is very smooth, the secratiors 
on the edge being faint and indistinct; the diameter is also very 
uniform, and there are coarse brown longitudinal striations, but 
no meduUa. The wool-hairs of the white ^^ariety are very dis- 



6o 



THE TEXTILE FIBRES. 



tinctly serrated on the edge, and the fibre is not so uniformly 
thick. The beard-hairs of the brown variety are comparatively 
few in number, are 5 to 6 cm. in length and about 60 /< in diameter, 
and the latter is very uniform. A very broad continuous medul- 
lary cylinder is present, 45 to 50 [x wide; the medullary cells 




Fig. 20. — Fibres of Alpaca. (Hohnel.) 
a, beard-hair containing medulla; b, wool-hair free from medulla; e, cusp-like 
scales, thin and broad; k, granulated streaks on the fibrous layer; m, medul- 
lary cylinders; z, small medullary cells. 

are very indistinct, but are filled with coarse granules of matter. 
The cortical layer shows occasional fissures, and the brown 
coloring-matter is principally distributed through the external 
cortical layer, though very irregularly. The beard- hairs of the 
white variety also occur rather sparingly; they are 20 to 30 cm. 
in length and 35 /t in thickness at the lower end and about 55 ,« 
towards the upper end. The medulla is broad and continuous, 
and nearly always filled with a coarsely granulated matter of a 
gray color. The medulla consists of a single row of short cylin- 



OTHER H^IR FIBRES. 6 1 

drical cells, but as the walls are very thin, the cells are to be 
seen only with difficulty. The cortical layer is coarsely striated 
and frequently shows fibrous fissures; the edge of the fibre is 
not sharply serrated. 

5. Vicuna Wool (or Vicogne) is another South American prod- 
uct obtained from Aucheuia viccunia, the smallest of this general 
class of goat-like camels. It is not a cultivated animal, and is 
evidently disappearing; hence the fibre is not met with in trade 
to any great extent at the present time. It is a soft, delicate fibre, 
usually of a reddish-brown color, and much resembles alpaca. 
It also shows the presence of a fine under-hair and a coarse upper- 
hair; the former is 10 to 20 /j. in diameter, while the latter is 75 /jl 
wide. The scales of the under-hair are very regular and rather 
easy to distinguish, but generally no medulla is to be seen. The 
cortical layer is finely striated and frequently contains fibrous 
fissures. The upper-hairs, however, show a well-de^Tloped 
medulla, mostly dark in color. The fibres of the under-hair are 
very uniform in diameter and about 20 cm. in length. 

An artificial wool substitute also goes by the name of vicuna or 
vicogne yarn, but bears no resemblance to the true South Ameri- 
can fibre.. It consists principally of a mixture of cotton with 
sheep's wool, but is frequently mixed more or less with wools 
and coarse beard-hairs of poor spinning qualities obtained from 
various goats (of Asia Minor), from camels, and from South 
American wools. It is of poor quality and generally yellowish 
brown in color. It is only used for felted materials or for very 
coarse fabrics. 

6. The Llama fibre exhibits scarcely any visible scales, but 
has wtU- developed isolated medullar}- cells. It also consists of 
two classes of fibres, both of which show longitudinal striations. 
The under-hair is 20 to 35 /j. in diameter, while the upper-hair 
averages 150 p.. The llama wool comes from the Auchenia llama, 
a cultivated animal. The wool from another variety, Auchenia 
huanaco, is used to some extent in South America, though it 
seldom appears as such in general trade. This latter animal is 
not cultivated, but is hunted wild, and is gradually disappearing. 
Huanaco and llama are nearly always mixed more or less with 



62 THE TEXTILE FIBRES. 

alpaca and brought into trade under the latter name. There is 
but little difference to be found among these three fibres, owing 
to the close relationship of the animals from which they are 
derived, and more especially as different portions of the fleece 
from all varieties of Auchenia give wools of entirely different 
quality with respect to color, fineness of staple, and purity from 
coarse stiff hairs; and the corresponding portions from the differ- 
ent animals are usually graded together. 

7. Camel's Hair is used to quite an extent in clothing material, 
and is characterized by great strength and softness. It has con- 
siderable color in the natural state, which does not appear capable 
of being destroyed by bleaching; hence camel's hair is either 
used in its natural condition or is dyed in dark colors. There are 
two distinct growths of fibre on the camel: the under-hair, which 
is a fine soft fibre, largely employed for making Jager cloth; and 
the upper- (or beard-) hair, which is much coarser and stiff er, and 
is mostly used for carpets, blankets, etc. Both fibres show faint 
markings of scales on the surface and well- developed longitudinal 
striations. The upper-hair always exhibits the presence of a 
well-defined medulla, which is large and continuous, while the 
under-hair either shows only isolated medullary cells or none at 
all. The diameter of the under-hair is from 14 to 28 {x, while 
the upper-hair averages 75 jx (see Fig. 21). The under-hairs are 
about 10 cm. in length, are rather regularly waved, and are usually 
yellow to brown in color; while the others are from 5 to 6 cm. 
long, and are dark brown to black in color. The epidermal scales 
of the latter are quite rough, which gives the edge of the fibre a 
saw-toothed appearance. T?he presence of large spots, or motes, 
of brown coloring-matter, especially in the medulla, is quite char- 
acteristic. These are usually granular in form. The beard- 
hairs of the camel are to be distinguished from corresponding 
cow-hairs by smaller diameter, thicker epidermis, and narrower 
medullary cells with thicker walls, which are generally darker in 
color than the enclosed pigment-matter. 

8. Cow-hair is extensively employed as a low-grade fibre for 
the manufacture of coarse carpet yarns, blankets, and a variety 
of cheap felted goods. It is seldom used alone, however, on 



OTHER. H^IR FIBRES. 63 

account of its short staple. It comes principally from Siberia. 
The diameter of cow-hair varies from 0.084 to 0.179 ^^^^- and 
the length from 1^-5 cm. The fibres occur in a variety of colors, 
including white, red, brown, and black. In its microscopic 
appearance the surface of the fibre is rather lustreless; the ends 
are very irregular, being blunt and divided. The medullary canal 
is well marked, occupying about one-half the diameter at the base 
and tapering towards the free end where it occupies only one-fourth 
the diameter. Isolated medullary cells are also of frequent 




Fig. 21. — Camel's Hair (X500). 

Showing one fibre colored and opaque, with no evidence of structure beyond a 
striated surface; and a second fibre with well-defined medullary cells. 



occurrence. Cow-hair (including also calf-hair) nearly always 
shows the hair-root, as the fibres are removed from the hide 
by liming and pulling. 

Cow-hair nearly always shows the presence of three kinds of 
fibres : 

(i) Thick, stiff beard-hairs from 5 to 10 cm. in length, and 
retaining a long narrow hair follicle; ohove this is the neck of 
the hair, containing a medullary cylinder consisting of a single 
series of cells as well as isolated medullary cells. At this part of 
the fibre the epidermal scales are very thin and broad, and the 



64 THE TEXTILE FIBRES. 

forward edges present a serrated appearance; the neck of the 
hair is about 120 //in thickness. Above this the hair rapidly 
increases to about 130 /t in thickness, and the medullary cylinder 
becomes broad (75 jx) and consists of narrow brick-shaped ele- 
ments, arranged one on top of the other. The cortical layer is 
finely striated, the epidermis is indistinct, and the edge of the 
fibre is smooth. The medullary cells are very thin-walled and 
contain a considerable amount of finely granulated matter. 
Towards the pointed end the fibre becomes colorless, and shows 
distinct fibrous fissures; the medullary cylinder disappears, but 
the epidermis is not altered. The chief difference between 
these hairs and the beard-hairs of the goat is that in the former 
the medullary cells consist of only a single series, and are very 
thin-walled, and are also frequently isolated from one another, 
while they are filled with finely granulated matter. 

(2) Soft, fine, beard-hairs possessing the same general struc- 
ture as the foregoing, but not so thick; the neck of the hair being 
75 // in diameter and not possessing any medulla. Above this the 
medullary cylinder consists of very thin-walled cells arranged in 
isolated groups; the epidermal scales overlap one another and 
are almost cylindrical, are narrow, and with finely serrated edges. 
About I cm. from the base the medullary cylinder becomes dis- 
continuous and breaks up into isolated medullary cells, which 
continue until the middle of the fibre is reached where they disap- 
pear completely; towards the pointed end of the fibre, they reap- 
pear and again become a continuous cylinder, consisting of only 
a single series of cells, however. These are well filled with dark 
medullary substance. 

(3) Very fine soft wool-hairs, free from medulla, and at most 
only I to 4 cm. in length, and frequently only 20 n in thickness. 
The epidermal scales are rough, causing the edge of the fibre to 
be uneven and have a serrated appearance. The hairs also show 
frequent longitudinal fibrous fissures. 

Calf-hair has the same general structure and appearance, 
though there is a greater amount of soft wool-hairs present. 

9. Minor Hair Fibres. — Horse-hair has a diameter of 80 to 
100 /x, and a length of i to 2 cm. (see Fig. 22). Like cow-hair, it 



OTHER H^IR FIBRES. 



65 



also occurs in a variety of different colors. Horse-hair is more 
lustrous than the foregoing, however, and though when viewed 
under the microscope the ends of the fibre 
arc irregular and often forked, they taper off 
to points. The medullary cylinder is rather 
large, occupying about two-thirds of the 
diameter at the base of the fibre, and taper- 
ing to about one-fourth of the diameter at 
the free end. The medulla consists of one 
to two rows of very narrow leaf-shaped cells. 
Isolated medullary cells are of frequent 
occurrence, especially at the point. The 
cortical layer frequently contains numerous 
short orifices or fissures. These remarks 
refer to the body- hairs of the horse; the 
hairs of the tail and mane are much longer, 
reaching from several inches to a foot or 
more. They find little or no use in ordi- 
nary textiles, but are much used as stuffing 

materials in the manufacture of upholstery. _ „ , . 

Fig. 22. — ^Horse-nair. 

Cat-hair varies in diameter from 14 to (H5hnei.) 

J • 1 iU r 4- ,^ '-pu w, broad meduUarv cylin- 

SA IX, and m length from i to 2 cm. The '^^^. ^^ thin-walled 'cells 
fibres occur in a variety of colors, and have of same; e, epidermal 

, , _,, , . . scales; /, fibrous fissures. 

a good lustre. The ends are quite regular 

and very pointed. The medullary canal contains a single 
series of regular cells occupying one-half to three-fifths of the 
diameter of the fibre. The cortical layer is well developed, and 
its inner face is grooved so as to fit over the medullary cells. 
There is a thin irregular epidermis which envelops the fibre 
(see Fig. 23). 

Rabbit-hair fibres are usually fight brown in color, and meas- 
ure from 34 to J 20 /J. in diameter, and from i to 2 cm. in length. 
The medullar}' canal is filled with several series of cells, quad- 
rangular in shape and with thin walls. They are also arranged 
in a very regular manner. By careful observation, spiral stria- 
tions may be noticed on the finer fibres. The epidermal scales 
are ver)' thick and their forward edges terminate in a sharp point 




66 



THE TEXTILE FIBRES. 



(see Fig. 24). Each scale is placed cornucopia-like into the next 
lower one, and is drawn out into i to 3 large waves. At the base 
of the fibre the medulla consists of a single row of cells, above 





tern 



Fig. 23. — ^Hairs of Cat. (Hohnel.) 
1 to 3, beard -hairs; 4 to 6, wool-hairs; gs, near the end of hair; gm, middle of 
hair; gb, near base of hair; wm, middle of wool-hair; ws, point of wool -hair j 
/, fibrous fissures; m, medullary cells; 2, serrated edge of medulla; r, tooth- 
Hke formation of epidermal scales. 

the middle this increases to 2 to 4 rows, and farther along the fibre 
the number of rows of cells increases up to 8, when the hair 
becomes very wide. Like most pelt-hairs, the fibres are somewhat 



OTHER HAIR FIBRES. 



67 



flattened at the base, and quite so at their broadest part. The 
cortical layer is only apparent towards the point where the medulla 
ceases. The wool- hairs of the rabbit are much thinner than the 






Fig. 24. — Hair of Rabbit. (Hohnel.) 
w, wool-hairs; gm, middle and broadest part of beard -hair; qii, cross-section of 
beard-hair; gb, base of beard-hair; e, cusp-like scales; i, medullary islands; 
m, n, medullary cells with granular contents; p, k, pigment plate-like cells. 

above, the greatest thickness being about 20 jn. Otherwise they 
correspond in structure to that part of the above fibre near the 
base. 



CHAPTER VI. 

SILK: ITS ORIGIN AND CULTIVATION. 

I. The silk fibre consists of a continuous thread which is spun 
by the silkworm. The worm winds the fibre around itself in 
the form of an enveloping cocoon before it passes into the chrysalis 
or pupal state. The cocoon is ovoid in shape and is composed 
of one continuous fibre, which varies in length from 350 to 1200 
meters (400 to 1300 yards), and has an average diameter of 0.018 
mm. In the raw state the fibre consists of a double thread 
cemented together by an enveloping layer of silk-glue, and is 
yellowish and translucent in appearance. When boiled off or 
scoured these double threads are separated, and the silk then 
appears as a single lustrous almost white fibre. Unlike both 
wool and cotton, silk is not cellular in structure, and is apparently 
a continuous filament devoid of structure. Hohnel, however, 
beheves that the silk fibre is not so simple in structure as it is at 
first believed. The surface of the fibre frequently shows faint 
striations, which may be rendered more apparent by treatment 
with chromic acid. Also by saturating the silk with moderately 
concentrated sulphuric acid and drying, then heating to 80° to 
100° C, the fibre will be disintegrated into small filaments, which 
would seem to indicate that it was made up of a number of minute 
fibrils firmly held together. 

The silkworm is a species of caterpillar, and though there are 
quite a number of these which possess silk-producing organs, 
the number which secrete a sufficient quantity of the silk sub- 
stance to render them of commercial importance is rather limited. 

The true silkworms all belong to the general class Lepidoptera, 

68 



SILK: ITS ORIGIN AND CULTIl^ATION. 69 

or scale- winged insects, and more specifically to the genus Bombyx. 
The principal species is the Bombyx mort, or mulberry' silkworm, 
which produces by far the major portion of the silk that comes 
into trade. The silk industry appears to have had its origin 
in China, and historically it dates back to about 2700 years B.C. 
In its early history it is said that the art of cultivating the silk- 
worm and preparing the fibre for use was a strictly guarded 
secret known only to the royal family. Gradually, however, 
it spread through other circles and soon became an important 
industr}' distributed universally throughout China. The Chinese 
monopolized the art for over three thousand years, but during 
the early period of the Christian era, the cultivation of the 
silkworm (or sericulture) was introduced into Japan. It also 
gradually spread throughout central Asia, thence to Persia and 
Turkey. In the eighth century, the Arabs acquired a knowledge 
of the silk industry, which soon spread through all the countries 
influenced by the Moorish rule, including Spain, Sicily, and 
the African coast. In the twelfth century we find sericulture 
practised in Italy, where it slowly developed to a national industry. 
In France sericulture appears to have been introduced about the 
thirteenth century, but it was not until the reign of Louis XIV 
that it assumed any degree of importance. In more recent 
times experiments have been made on the cultivation of the 
silkworm in almost every civilized country.* 

According to the number of the generations they produce in a 
year, the Bombyx mori are divided into two classes: the members 
of the one reproduce themselves several times annually, and are 
termed poly voltine ; their cocoons are small and coarse. The other 
worms have only one generation in a year, and hence are termed 
annual. ■ The cocoons of the latter are much superior to those of 
the preceding. The cultivation of the silkworm starts with the 
proper care and disposition of the eggs. With the annual worms 
there elapse about ten months between the time the eggs are 
laid and their hatching. The hatching only takes place after the 

* Mr. Samuel Whitmarsh, about 1838, appears to have been about the first 
to attempt sericulture in America. He cultivated the Motus mulHcaulis in 
Pennsylvania, but the experiment proved to be a failure. 



70 THE TEXTILE FIBRES. 

eggs have been exposed to the cold for some time and are sub- 
sequently subjected to the influence of heat. When the eggs 
are laid by the silk-moth they are received on cloths, to which 
they stick by virtue of a gummy substance which encloses them. 
For the first few days they are hung up in a room, the air of which 
is kept at a certain degree of humidity — about semi- saturation. 
Then comes a period of hibernation, during which the eggs c^re 
kept in a cool place; at present artificial refrigeration is resorted 
to in many establishments. The period of hibernation lasts 
about six months. After this comes the period of incubation, 
in which the embryo is gradually developed into a worm and 
the egg is hatched. The hatching usually takes .place in heated 
compartments in which the temperature is carefully regulated. 
The period of incubation occupies about thirty days, though 
this time has been shortened considerably by certain artifices, 
such as the action of electric discharges. Twenty-five grams 
of eggs will yield about 36,000 worms on hatching. The cater- 
pillar, on first making its appearance, is about 3 mm. long, and 
weighs approximately 0.0005 gram. Its growth and development 
proceeds with extraordinary rapidity, and during its short exis- 
tence it undergoes a number of very curious transformations. 
Under normal conditions there elapse thirty-three to thirty-four 
days between the time of the hatching of the egg and the com- 
mencement of the spinning of the cocoon. During this time 
the worm sheds its skin four times, and these periods of moulting 
divide the life-history of the worm into five periods. Almost 
immediately after being hatched the worms devour mulberry 
leaves with great avidity, and continue to eat throughout the 
five periods, though v/hen about to shed their skins they stop 
eating for a time and become motionless. The size and weight 
of the caterpillars increase with remarkable rapidity; during 
the fifth period they reach their greatest development, measur- 
ing 8 to 9 cm. in length and weighing 4 to 5 grams; and after 
thus maturing they begin to diminish in weight. The following 
table by Vignon shows the relative weights of the silkworm during 
the different stages of its existence. The figures refer to the 
weight of 36,000 worms: 



SILK: ITS ORIGIN /iND CULTIVATION. 7i 

Grams. 

Eggs 25 

Worms (36,000) 17 

First period (5 to 6 days) 255 

Second period (4 to 5 days) i)598 

Third period (6 to 7 days) 6,800 

Fourth period (7 to 8 days) 27,676 

Fifth period (11 to 12 days) 161,500 

At maturity 131,920 

Cocoons 76,250 

Chrysalis alone 66,300 

Butterflies, half of each sex 99)865 

Thus we see that in less than forty days the weight of the 
silkworm increases almost 10,000 times. 

When the worm has reached the limit of its growth, it ceases 
to eat, and commences to diminish in size and weight. The time 
is now ready for the spinning of its cocoon; the worm perches 
on the twigs so disposed to receive it and exudes a \'iscous fluid 
from the two glands in its body whei'cin the silk secretion is 
formed. The liquid flows through two channels in the head of 
the worm, into a common exit-tube, where also flows the secre- 
tion of two other symmetrically situated glands which cements 
the two threads together. Consequently the thread of raw 
silk is produced by four glands in the worm; the two back ones 
secrete the fibroin which gives the double silk-fibre, while the 
two front glands secrete the silk-glue or sericin which serves as an 
integument and cementing substance. On emerging from the 
spinneret in the head of the w^orai, the fibre coagulates on con- 
tact with the air. 

The worm weaves this thread around itself, layer after layer, 
until the cocoon or shell is gradually built up. It requires about 
three days for the completion of the cocoon. After finishing the 
winding of its cocoon, the enclosed silkworm undergoes a remark- 
able transformation, passing from the form of a caterpillar into 
an inert chrysalis or pupa, from which condition it rapidly devel- 
ops into a butterfly, which then cuts an opening through the 
cocoon and flies away. As the integrity of the cocoon-thread 
would be destroyed by the escape of the butterfly, and hence 
lose much of its value, it is desirable that the development of the 
chrysalis be stopped before it proceeds too far, and this is accom- 



72 



THE TEXTILE FIBRES. 



plished by killing it by a heat of 70 to 80° C. or by live steam. 
The cocoons at this stage weigh from 1.25 to 2.5 grams each, 
and of this 15 to 16 per cent, is silk fibre. Of this amount, 
however, only 8 to 10 per cent, is available for silk filaments, the 
remainder, 6 to 7 per cent., constituting waste and broken threads, 
and is utilized for spun silk.* As to the thickness of the filaments 
of .silk in the cocoon, Haberlandt furnishes the following data: 



Species. 


Exterior Layer 
of Cocoon. 


Middle 
Layer. 


Interior 
Layer. 




0.030 mm. 
0.025 " 
0.030 " 
0.020 " 
0.025 " 


0.040 mm. 
0-035 " 
0.040 " 
0.030 " 
0-035 " 


0.025 mm. 
0.025 " 
0.020 " 
0.017 " 
0.020 " 


Yellow French 


Green Japan 

White Japan 


Bivoltin worms 







* There are several different varieties of waste silk, as follows: 

1. The refuse obtained in raising the silkworm, called Watt silk in commerce. 
Owing to the scientific methods of silk-culture in Europe, the amount obtained 
from this source is very small. China, however, exports a large amount yearly. 
This material contains about 35 per cent, of pure silk, and is the poorest grade 
of waste silk on account of its irregularity. 

2. The irregularly spun and tangled silk on the outside of the cocoon, called 
floss silk or Prisons. It comprises from 25 to 30 per cent, of the entire cocoon, 
and is valuable owing to its purity and fine quality. 

3. The residue of the cocoon after reeling; this forms an inner parchment-like 
skin, and in commerce goes under the name of ricotti, wadding, neri, Galettame, 
Basinetto, etc. 

4. Cocoons imperfect from various causes, such as being punctured by the 
worms, becoming spotted by pupa breaking, etc. These are known as cocons, 
perces, piques, tarmate, rugginose, etc. It forms a valuable material for floss 
silk spinning. The best grades contain 75 to 85 per cent, pure silk, and the 
average is about 65 per cent. 

5. Double cocoons, which, in spite of the difl&culty in reeling, were formerly 
used for special purposes. Now such cocoons are converted into waste which 
is known as Strussa. 

6. Waste obtained in reeling the cocoons, known as Frisonnets. 

7. A great variety of wild silks, which, for the most part, cannot be reeled, 
and are, therefore, first converted into waste. A large quantity of wild silk, 
even though it can be reeled, is torn up for waste. 

8. Waste made by reeling, spooling, and other processes of working silk. 

Silk shoddy resembles wool shoddy in origin, consisting of recovered fibres 
from manufactured silk goods. It nearly always contains isolated fibres of both 
wool and cotton, and frequently mixtures of diS'erent kinds of silk. There may 
also occur boiled-off, soupled, and raw silk, and mixtures of organzine and spun 
silk. Different colors are also usually present. The fibres, as a rule, are quite 



SILK: ITS ORIGIN AND CULTIl^/lTION. 



73 



The double silk fibre as it exists in the cocoon is known as the 
have, and the single filaments are called brins. 

The size of the single silk filament as it comes from the cocoon 
averages 2\ deniers.* The following table gives the approximate 
size of filaments of mulberry silk from different countries: 



Country. 



Spain. . . 
France. . 

Italy 

Syria. . . . 
Caucasus 
Brousse. . 
Japan. . . 
China. . . 
Bengal. . 



Weight in 500 Meters 



in Deniers 


in Milligr. 


30 


163 


2.6 


138 


2.4 


128 


2-4 


128 


2-3 


125 


2.2 


117 


2. 1 


113 


2.0 


108 


1.2 


64 



2. Wild Silks. — Besides the Bomhyx mori, or mulberry silk- 
worm, there are other associated varieties of caterpillars which 
also produce silk in sufficient quantity to be of considerable 
commercial importance. Due to the fact that such silkworms 
are not capable of being domesticated and artificially cultivated 
Hke the mulberry worms, the silk obtained from them is called 
wild silk. Of this latter there are several commercial varieties, 
of which the most important are here given. 

short, being about a centimeter in length. Due to these components, silk shoddy 
is comparatively easy to recognize under the microscope. 

* The fineness or size of the silk thread is expressed by a number known as 
titre (in French) or titolo (in Italian); this gives the number of urats of certain 
weight (denier) a skein of certain length will weigh. Several different standards 
are in use at the present time, among which are the following: 

Weight in Length in 

MilHgrams. Meters. 

Denier (legale) o . 05 450 

Denier milano 0.051 476 

Denier turino o. 0534 476 

Old denier Lyonese 0.0531 476 

New denier Lyonese 0.0531 500 

Denier international 0.05 500 

The titre is usually expressed in the form of a fraction, representing limits of 
variation, as all skeins are not of absolutely the same size. A silk marked 18/20 
for instance, would mean that it varied from 18 to 20 deniers. 



74 THE TEXTILE FIBRES. 

AnthercEa yama-mai, a native of Japan, is a green-colored 
caterpillar which feeds on oak-leaves. Its cocoon is large and 
of a bright greenish color. The silk bears a close resemblance 
to that of the Bombyx mori, but is not as readily dyed and bleached 
as the latter. 

Antheraa pernyi is a native of China; besides growing wild, 
it has been domesticated to some extent. This worm also feeds 
on oak-leaves, but is of a yellow color. Its cocoon is quite large, 
averaging over 4 cm. in length, and is of a yellowish to a brown 
color. 

Anther (Ea assama is a native of India; it gives a large cocoon 
over 45 mm. in length. 

Anthercea mylitta is another Indian variety, and furnishes 
the so-called tussah silk, though this term has also been applied in a 
general manner to all varieties of wild silk. The worms feed on 
the leaves of the castor-oil plant, and give very large cocoons, 
reaching 50 mm. in length and 30 mm. in diameter. The color 
varies from a grey to a deep brown. 

Another variety of silkworm which is to be found both in 
Asia and America is the A ttacus ricini; it gives a very white 
and good quality silk, the production and value of which is in- 
creasing every year. A species of this class, known as A ttacus 
atlas, is perhaps the largest moth known; it spins open cocoons 
and gives the so-called Fagara, or Ailanthus, silk. 

Wild silks are much more difhcult to unwind from the cocoons 
than that of the mulberry silkworm. The silk is also much 
darker in color; it also has less strength and elasticity, and is 
much more difficult to dye and bleach. 

Tussah (or tussur) silk (as well as other wild silks) is chiefly 
employed for making pile-fabrics, such as velvet, plush, and 
imitation sealskin. 

3. The Microscopical and Physical Properties of Silk. — Under 
the microscope raw silk exhibits an appearance which readily 
distinguishes it from the textile fibres. It is seen as a smooth struc- 
tureless filament, very regular in diameter and very transparent. 
The two brins in the have of raw silk give beautiful colors with 
polarized light when examined microscopically. The sericin 



SILK: ITS ORIGIN AND CULTIVATION. 75 

coating, however, appears to have no such action. The latter, 
being hard and brittle, on bending develops transverse cracks 
which are very apparent under the microscope. 

The fibre of Bombyx mori is only rarely striated longitudinally, 
and when such striations do appear they always run parallel to 
the axis of the fibre. When treated with dilute chromic acid 
very fine striations are caused to appear. Wild silks often show 
fibres which are twisted on their axes, and the layer of gum is 
usually more or less granular. Anthercea mylitia shows rather 
frequent oblique striations, and does not exhibit much play of 
color with polarized light. This latter characteristic is also true 
of AnihercEa yama-mai. The other silks give colors with polar- 
ized light very nicely. Silk fibres are colored a deep red with 
alloxan thin; fuchsin also gives a red color. On treatment 
with sugar and sulphuric acid, silk is first colored a rose-red and 
then dissolves; hydrochloric acid gives a violet color and then 
dissolves the fibre. lodin colors the fibres yellow to reddish 
brown. 

Carded silk, which has been worked up from imperfect cocoons, 
etc., can usually be recognized under the microscope by the irreg- 
ular and torn appearance of its external layer of gum. 

The inner layers of the cocoon consist of a yellow parchment- 
like skin, and when examined under the microscope exhibit a 
matrix of sericin, in which numerous double fibres are imbedded, 
usually very much fattened in cross-section (Fig. 25, a). These 





(a) 

Fig. 25. — Cross-sections of Silk Fibre. 

a, from inner part of cocoon; b, from middle layers of cocoon; c, from outer part 

of cocoon; /, fibre of fibroin; s, layer of sericin. 

inner layers, of course, are not capable of being reeled with the 
rest of the cocoon, and are used for waste silk. The cross-sec- 
tions of the fibres from the middle portion of the cocoon, con- 



76 THE TEXTILE FIBRES. 

stituting the reeled silk, are much more rounded in form and 
surrounded with a thinner layer of sericin (see Fig. 2^b). The 
fibres of the outer part of the cocoon, also utilized for waste silk, 
exhibit a rather irregular cross-section (see Fig. 25c). 

When raw silk is examined under the microscope it will be 
seen that the appearance is by no means regular, owing to the 
broken and torn surface of sericin which surrounds the fibre (see 




Fig. 26.— Fibres of Raw Silk (X500). 
Showing the double filament and the irregular coating of silk-glue. 

Fig. 26). Frequently, the two filaments of fibroin are distinctly 
separated from one another for considerable distances, the inter- 
vening space being filled in with sericin. Occasionally, the layer 
of sericin is seen to be entirely absent, having been removed by 
breaking or rubbing off. The sericin layer also shows frequent 
transverse fissures, which are merely cracks caused by the break- 
ing of the sericin in the bending or twisting of the fibre. Creases 
and folds in the sericin, as well as irregular lumps, are also of 
frequent occurrence. All of these markings are in. no wise struc- 
tural, and only occur in the sericin layer. At times the fibroin 
fibre exhibits structural changes in places, such as discontinua- 
tions; but these only occur in defective and unhealthy silk, and 
give rise to weak places. These are caused by the fibroin not 
being secreted by the gland with sufficient rapidity. 



SILK: ITS ORIGIN ^ND CULTIl^/ITION. 



77 



The microscopic appearance of the wild silks is very different 
from that "of the Bombyx mori. The fibres are very broad and 
thick, and in cross-section are very flat, and often triangular in 
outline. Longitudinally, they show very distinct striations, and 
peculiar flattened markings, usually running obliquely across the 
fibre, and in which the striations become more or less obliterated. 




Fig. 27.— Wild Silks. 
A, view of narrow side; B, view of broad side; C, cross-sections; D, cross- 
section of double fibre; cr, cross-marks on fibre. 



These cross-markings are caused by the overlapping of one fibre 
on another before the substance of the fibre had completely 
hardened; in consequence of which, these places are more or less 
flattened out (see Fig. 27). The striated appearance of wild silk 
is evidence that structurally the fibre is composed of minute fila- 



78 



THE TEXTILE FIBRES. 



ments; in fact, the latter may readily be isolated by maceration 
in cold chromic acid. According to Hohnel, these structural 
elements are only 0.3 to i 5 /< in diameter; they run parallel to 
each other through the fibre, and are rather more dense at the 




Fig. 28.— Tussah Silk (X340). (Hohnel.) 

A, view of narrow side; B, view of broad side; C, flat surface of single fibre show- 
ing two thin cross-marks at i and 2; /, air canals; g, fibrillas; D, cross- 
section; i, inner layers; r, denser marginal layers. 



outer portion of the fibre than in the inner part (see Fig. 28). 
Besides the fine striations on the fibres of wild silk caused by 
their structural filaments, there are also to be noticed a number 
of irregularly occurring coarser striations. These latter appear 
to be due to air- canals, or spaces between the filaments of the 
fibre (see Fig. 29). 



SILK: ITS ORIGIN AND CULTIV/ITION. 



79 



Hohnel is of the opinion that there is really no difference 
in kind between the structure of wild silk and that of cultivated 
silk; that is to say, the fibroin fibre of the latter is also composed 
of structural filaments, only they fuse into one another in a more 
homogeneous manner on emerging from the fibroin glands, 
thus rendering it more difficult to recognize them superficially. 




Fig. 29. — Cross-section of Wild Silk. (Hohnel.) 
A, diagramatic drawing of section; i, air-space; g, ground matrix; /, fibrillae; 
r, marginal layer; B, end of fibre of tussah silk, swollen in sulphuric acid; 
C, cross-section of fibre of tussah silk swollen in sulphuric acid. 

This view is upheld somewhat by the fact that a slight striated 
appearance may be noticed when the silk fibre is macerated in 
chromic acid solution. This apparent structure of the silk fibre, 
however, may also be due to another cause. If a plastic glutinous 
mass (such as melted glue, for instance) be pulled out into the 
form of a thread and allowed to harden, it will be found to 
exhibit the same striated structure as the silk fibre; and this 
structure will be more apparent if the thread is pulled out and 
hardened more rapidly. The liquid fibroin in the glands of 



8o 



THE TEXTILE FIBRES. 



the worm is a plastic glutinous mass analogous to melted glue,, 
and is pulled out into the form of a thread by the action of the 
worm in winding its cocoon; hence it would be natural to expect 
a striated structure similar to that observed in the thread of 
glue. Thus, it is possible to account satisfactorily for the struc- 
ture of the silk fibre in a perfectly natural manner, without having 




Fig. 29a. — Showing Different Stages in Growth of Silkworm. 

A, silkworm in fifth period, full size; B, moth or butterfly; C, chrysalis or pupa; 

D, eggs of moth; E, diagram showing cocoon and method of winding. 

recourse to a very doubtful organic process in the formation of 
the fibre, such as is supposed to be the case by Hohnel. 

Raw silk is quite hygroscopic, and under favorable circum- 
stances will absorb as much as 30 per cent, of its weight of moist- 
ure, and still appear dry. It is therefore customary to determine 
the amount of moisture in each lot at the time of sale. This 
is called conditioning, and is usually carried out in official labora- 
tories. The amount of moisture which is legally permitted is 
II per cent. 



SILK: ITS ORIGIN AND CULTIVATION. 



8i 



Being a bad conductor of electricity, silk is readily electritied 
by friction, which circumstance at times renders it difificult to 
handle in the manufacturing processes. The trouble can be 
overcome to a great extent by keeping the atmoshpere moist. 

The most striking physical property of silk, perhaps, is its 
high lustre. The lustre only appears after the silk has been 
scoured and the silk-gum removed. The lustre of silk is affected 
more or less by the various operations of dyeing and mordanting, 
and especially v^hen the silk is heavily weighted. After dyeing, 





Fig. 296. — Showing Methods of Reeling the Silk Fibre from the Cocoon. 

especially in the skein form, silk usually undergoes what is termed 
a lustring operation, which consists generally in stretching the 
hanks strongly by twisting, and simultaneously steaming under 
pressure for a few minutes. This process seems to bring back 
to the dyed silk its lustre to a considerable extent. The lustre is 
also considerably affected by the method of dyeing and the 
chemicals employed in the dye-bath; it has been found that 
the addition of boiled-off liquor (the soap solution of sericin 
obtained in the degumming of raw silk) to the dye-bath has 
the result of preservdng the lustre of the dyed silk better than 
anything else, and in consequence, boiled-off liquor is nearly 
always employed as the assistant in dyeing in preference to 
Glauber's salt or common salt. 

Silk is also distinguished by its great strength. It is said that 
its tensile strength is almost equal to that of an iron wire of equal 



82 



THE TEXTILE FIBRES. 



diameter. The silk fibre is also very elastic, stretching 15 to 20 
per cent, of its original length in the dry state before breaking. 
Degummed or boiled-off silk is much lower in strength and 
elasticity than raw silk, the removal of the silk-gum apparently 
causing a decrease of 30 per cent, in the tensile strength and 
45 per cent, in the elasticity. The weighting of silk also causes a 
decrease in its strength and elasticity. 

The following table gives the diameter, elasticity, and tensile 
strength of the cocoon-thread of the chief varieties of silks (Wardle, 
Jour. Soc. Arts, xxxiii. 671): 



Name of Silk. 


Coun- 
try. 


Diameter, Elasticity, 
Ins. Ins. in i Ft. 


Tensile 
strength, 
Drams. 


Size of 

Cocoon, 

Ins. 




Outer 
Fibres. 


Inner 
Fibres. 


Outer 
Fibres. 


Inner 
Fibres. 


Outer 
Fibres. 


Inner 
Fibres. 


Bombyx mori 

Bombyx mori 

Bombyx mori 

Bombyx fortunatus 

Bombyx textor 

Antheraea mylitta. . . 

Attacus ricini 

Attacus cynthia. . . . 
Antheraea assama . . 

Actius selene 

Attacus atlas 

Antheraea yama-mai. 


China 
Italy 
Japan 
Bengal 
India 
India 
India 
India 
India 
India 
India 
Japan 
India 
China 


. 0005 2 
.00053 
.00057 
.00045 
. 00042 
.00161 
. 00085 
. 00083 
.00128 
.00100 
.00102 
.00088 


. 0007 I 
. 00068 
. 00069 
. 0005 I 
. 00047 
.00172 
. 00093 
.00097 
.00125 
.00109 
.00111 
. 00096 
00120 


1-3 
1.2 
1.2 
1.8 

1-5 
1.9 

1-7 
2.6 
2.4 
2.0 
1.9 
2.0 


1.9 
1.9 
1.4 

2-3 

1.9 

2.7 

2.0 ■ 

2.9 

2.9 

2.8 

2.8 

4.0 


1.6 
1.9 
2.0 
1.6 
1.4 
6.6 

T--S 

2.4 

2.8 

2.4 

2. I 

6.8 


2 
2 

3 
2 
2 
7 

3 
3 
4 
4 
4 
7 


6 
6 

I 
8 
6 
8 


5 
8 


I 
5 


1. 1X0.5 
1.2X0.6 
I. 1X0.6 
1.2X0.5 
I. 2X1. 5 
1.5X0.8 
1.5X0.8 
1.8X0.8 
I.8XI-0 
3.0X1.2 
3.5X0.8 
1.5X0.8 
2.0X0.8 


Antheraea pernyi. . . . 


.00118 


.00138 


2.0 


2.7 


3-2 


5-8 


1.6X0.8 



The density of silk in the raw state is 1.30 to 1.37, while 
boiled-off silk has a density of 1.25. 

Another property of silk which is peculiar to this fibre, ordi- 
narily, is what is termed its scroop; this refers to the crackling 
sound emitted when the fibre is squeezed or pressed. To this 
property is due the well-known rustle of silken fabrics. The 
scroop of silk does not appear to be an inherent property of the 
fibre itself, but is acquired when the silk is worked in a bath of 
dilute acid and dried without washing. A satisfactory explana- 
tion to account for the scroop has not yet been given; it is 
probably due to the acid hardening the surface of the fibre. 



SILK: ITS ORIGIN AND CULTiyATION. 83 

Mercerized cotton can also be given a similar scroop bv such 
a treatment with dilute acetic acid. Wool, under certain con- 
ditions of treatment, can also be given this silk-like scroop, as, 
for instance, when it is treated with chloride of lime solutions 
or with strong caustic alkalies. 

4. Silk-reeling. — ^The silk fibre as it appears in trade for use 
in the manufacture of textiles is obtained by unreeling the cocoon. 
After the cocoons have been spun by the silkworms they are 
heated in an oven for several hour': at a temperature of 60° to 70° C. 
for the purpose of killing the puoa or chr)'salis contained within, 
before the latter shall have developed sufficiently to begin cutting 
its way through the envelope and thus destroy the continuity of 
the cocoon-thread. Another method of operation is to steam the 
cocoons; this requires only a few minutes to kill the pupa, and 
is said to be preferable to the oven-heating, as it causes less damage 
to the fibre, and at the same time considerably softens the silk- 
glue, thus rendering the subsequent process more easy. After 
the killing of the worms is accomplished the cocoons are sorted 
into several grades, according to size, color, extent of damage, 
etc., after which they are ready for reeling. This is entirely a 
mechanical process requiring much skill. The cocoons are 
soaked in warm water until the silk-glue is softened; the operator 
seizes the loose ends of several fibres together on a small brush 
and passes them through the porcelain guides of a reel, where 
they are twisted together to form threads of sufficient size for 
weaving. Two threads are formed simultaneously on each reel, 
and are made to cross and rub against each other to remove 
twists in the fibre (see Fig. 296), and also to rub the softened 
silk-glue coverings together in order that the fibres may become 
firmly cemented and form a uniform thread. The product so 
obtained is termed raw silk or grege; floss silk, which is used 
for making spun silk, is the term applied to the waste result- 
ing from short and tangled fibres from the exterior of the 
cocoon, and from those cocoons which have been broken by 
the moth in escaping. Raw silk is classified into two grades: 
(a) Organzine silk, which is made from the best selected cocoons, 
and is chiefly used for warps on account of its greater strength; 



84 THE TEXTILE FIBRES. 

and (b) Tram silk, which is made from the poorer quahty cocoons, 
and is mostly employed for filling. Floss or waste silk cannot 
be reeled, so the cocoon- threads are scoured in a solution of soda 
and soap, and afterwards combed and carded in special machines. 
The better quality and longer fibre is worked up into what is 
known as florette silk, while the shorter fibres are carded and 
spun into bourette silk. Floss silk is also known as chappe or 
echappe silk. 



CHAPTER VII. 

CHEMICAL NATURE AND PROPERTIES OF SILK. 

I. Chemical Constitution. — ^The glands of the silkworm appear 
to secrete two transparent liquids. The one, fibroin, constituting 
from one-half to two-thirds of the entire secretion, forms the inte- 
rior and larger portion of the silk fibre; the other, serici'n, also 
called silk-glue, forms the outer coating of the fibre. The latter 
substance is yellowish in color, and is readily soluble in boiling 
water, hot soap, and alkaline solutions. As soon as discharged 
into the air the fluids from the spinneret solidify, and coming into 
contact with each other at the moment of discharge, are firmly 
cemented together by the sericin. 

The amount of sericin present in raw silk is about 25 per 
cent., and this causes the fibre to feel harsh and to be stiff and 
coarse. Before being manufuctured into textiles the raw silk is 
subjected to several processes with a view to making it soft and 
glossy. The first treatment is called discharging, stripping, or 
ungumming, and has for its purpose the removal of the silk-glue. 
It is really a scouring operation, the silk being worked in a soap 
solution * at a temperature of 95° C. In this process the silk 
loses from 20 to 30 per cent, in weight, but becomes soft and 
glossy. After several successive scourings the soap solution 
becomes heavily charged with sericin, and is subsequently util- 
ized in the dye-bath as an assistant under the name of boiled-off 
liquor. 

* Alkaline carbonates are not to be recommended for silk-scouring, as they 
are liable to injure the fibre, especially at elevated temperatures. Soft water 
should also be employed, as lime makes the fibre brittle. 

85 



86 



THE TEXTILE FIBRES. 



According to Mulder, samples of yellow Italian silk analyzed 
as follows : 

Per Cent. 

Silk fibre 53.35 

Matter soluble in water 28 . 86 

" " " alcohol 1 . 48 

" " " ether o.oi 

" " " acetic acid 16.30 

He gives the chemical composition of the silk fibre as follows: 

Per Cent. 

Fibroin 53-37 

Gelatin 20 . 66 

Albumin 24 . 43 

Wax 1 . 39 

Coloring-matter o . 05 

Resinous and fatty matter o . 10 

According to Richardson, mulberry silk has the following 
composition : 

Per Cent. 

Water 12 . 50 

Fats o. 14 

Resins 0.56 

Sericin 22 . 58 

Fibroin 63 . 10 

Mineral matter 1.12 

Analysis of samples of mulberry silk is given by H. Silbermann 
as follows : 



White. 



Cocoons. Raw 



Yellow. 



Cocoons. Raw, 



Fibroin 

Ash of fibroin 

Sericin 

Wax and fat. 
Salts 



73-59 
0.09 

22.28 
3.02 
1.60 



76.20 
0.09 

22.01 
1.36 
0.30 



70.02 
o. 16 

24.29 
3-46 
1.92 



72.35 
o. 16 

23-13 

2-75 
1.60 



The amount of ash in boiled-off silk will vary somewhat 
according to the origin of the silk, but will average about 0.50 
per cent. In raw silk the average amount of ash will be about 
I per cent. In yama-mai silk the ash may reach as high as 8 
per cent. 



CHEMICAL NATURE AND PROPERTIES OF SILK. 87 

Fibroin is a proteoid somewhat analogous to that contained in 
wool, and, like the latter, it is no doubt an amido-acid.* Mulder 
gives the analysis of fibroin as follows : 

Per Cent. 

Carbon 48 . 80 

Hydrogen 6.23 

Oxygen 25 . 00 

Nitrogen 19 . 00 

Vignon analyzed samples of highly purified silk,t and gives 
the following figures: 

Per Cent. 

Carbon 48 . 3 

Hydrogen 6.5 

Nitrogen 19.2 

Oxj'gen 26.0 

The proportion of fibroin in raw silk has been variously 
stated by different observers, and appears to differ with the 
method employed for its determination. The figure given by 
Mulder (see above) of 53.35 per cent, was obtained by boiling 
the raw silk with acetic acid. By the action of a 5 per cent, 
solution of cold caustic soda, Stadeler obtained 42 to 50 per cent, 
of fibroin. Cramer obtained 66 per cent, by heating raw silk 
in water at 133° C. under pressure. Francezon reports 75 per 
cent, of fibroin by twice boiling the silk in a solution of soap and 
then treating with acetic acid. Vignon, by carefully purifying 
the fibroin by suitable treatment, obtained 75 per cent. 

* Richardson suggests the following structural formula for fibroin, allowing x 
to represent a hydrocarbon residue: 

^CO— NH-^ 

The decomposition of fibroin by saponification with potash would then be 

/NH— CO\ /NH, 

0(/ V+2KOH=2:x:<; 

\CO— NH/ ^CO.OK 

•j- Vignon prepared pure fibroin in the following manner: A lo-gram skein 
of raw white silk is boiled for thirty minutes in a solution of 15 grams of neutral 
soap in 1500 c.c. water; rinse in hot, then in tepid water; squeeze and repeat the 
treatment in a fresh soap-bath; rinse with water, then with dilute hydrochloric 
acid, again with water; finally, wash twice with 90 per cent, alcohol. The fibroin 
thus obtained leaves only o.oi per cent, of ash on ignition. {Compt. rend., cxv. 
17. 613)- 



88 THE TEXTILE FIBRES. 

Unlike keratin, the proteoid of wool, fibroin contains no sul- 
phur, and is much more constant in its composition. The empiri- 
cal formula for fibroin as given by Mulder is CigNagNgOg- Mills 
and Takamine give the formula as Cj^HggNgOa, while Schiitzen- 
berger gives CjjPIioyNj^Ojg. Cramer arrives at the same formula 
as Mulder, while Richardson {Jour. Soc. Chem. Ind., xii. 426) 
gives CeoHg^NigOzs- Vignon's formula for specially purified 
fibroin is CzzH^^NioOiz-* 

The presence of the amido-group in fibroin has been shown^ 
as in the case of wool (see page 37), by diazotizing the fibre 
with an acid solution of sodium nitrite, then washing and treating 
with solutions of various developers, such as phenol, resorcinol, 
alpha- and beta-naphthols, etc., whereby the fibre becomes dyed 
in different colors. 

From its action towards alcoholic potash Richardson con- 
cludes that silk-fibroin is more probably an amido- anhydride 
rather than an amido-acid. When boiled for a long period with 
dilute sulphuric acid fibroin is dissolved to a yellowish brown, 
liquid, leaving as a residue only a small amount of what is appar- 
ently a fatty acid. From this decomposition product Weyl 
{Ber., XXI. 1529) succeeded in isolating 5.2 per cent, of tyrosin,, 
7.5 per cent, of glycocin, and 15 per cent, of a crystalline com- 
pound which was apparently alpha-alanin. Towards Millon's and 
Adamkiewitz's reagents fibroin gives the usual reaction of pro- 
teids, and it also gives the biuret test.f According to Richardson, 

* Silbermann found that fibroin heated with a solution of barium hydrate 
under pressure was decomposed with the formation of oxahc, carbonic, and acetic 
acids, together with an amido body approximating the formula CggHj^iNjiO^g. 
The latter compound is said to undergo further decomposition with the formation 
of tyrosin, glycocin, alanin, amido-butyric acid, and an amido-acid of the actylic 
series. 

t Millon's reagent consists of a solution of mercurous nitrate containing nitrous 
acid in solution. It is prepared by treating i c.c. of mercury with lo c.c. of nitric 
acid (sp. gr. 1.4), heating gently until complete solution is effected, then diluting 
the solution with twice its volume of cold water. When a solution of a proteid 
is treated with this reagent a white precipitate is first formed which turns brick- 
red on boiUng; a solid proteid becomes red when boiled with the reagent. Adam- 
kiewitz's test is to dissolve the proteid in glacial acetic acid, and then add con- 
centrated sulphuric acid to the solution, when a fine violet color will be produced, 
and the liquid will exhibit a faint fluorescence. The biuret test is to add a few 



CHEMICAL NATURE AND PROPERTIES OF SILK. 89 

silk-fibroin will absorb 30 per cent, of iodin when treated with 
Hubl's reagent. Attempts have been made to acetylize fibroin, 
but without success. 

Fibroin is insoluble in ammonia and solutions of the alka- 
line carbonates; neither is it dissolved by a i per cent, solution 
of caustic soda, but stronger solutions affect it, especially if hot. 
From its solution in caustic soda fibroin may be reprecipitated 
by dilution with water. Fibroin is also soluble in hot glacial 
acetic acid, and in strong hydrochloric, sulphuric, nitric, and 
phosphoric acids. Alkaline solutions of the hydroxides of such 
metals as nickel, zinc, and copper also dissolve fibroin. 

If silk-fibroin is dissolved in cold concentrated hydrochloric 
acid, and the solution be allowed to stand sixteen hours at the 
ordinary temperature with three times its volume of hydro- 
chloric acid (sp. gr. 1.19), it will no longer be precipitated by the 
addition of alcohol. The fibroin appears to have suffered hy- 
drolysis, being converted into a body similar to peptone. This sub- 
stance may be separated out by steaming the above solution under 
diminished pressure. If its aqueous solution be neutralized 
with ammonia and some trypsin ferment be added, ty rosin will 
begin to crystallize out in a few hours. 

Sericin, according to the analysis of Richardson, has the 
following composition : 

Per Cent. 

Carbon 48 . 80 

Hydrogen 6.23 

Oxygen 25.97 

Nitrogen 19 . 00 

and its formula is given as CieHagNsOg. It is considered as 
probably being an alteration of fibroin; strong hydrochloric acid 
is said to convert the latter into sericin ; the conversion is supposed 
to take place by assimilation of water and oxygen: 

CisH^aNsOe+H^O+O =C,6H,,N,0«. 

Fibroin Sericin 



drops of a dilute solution of copper sulphate to the solution of proteid; on then 
adding an excess of caustic soda solution the precipitate which at first formed will 
"be dissolved with the production of a fine violet coloration. 



90 THE TEXTILE FIBRES. 

Sericin may be obtained in a pure condition by first boiling a 
sample of raw silk in water for several hours, after which the 
sericin is precipitated by lead acetate.* On treatment with 
dilute sulphuric acid sericin yields a small quantity of leucin 
and tyrosin, but no trace of glycocoU, the principal product 
formed being a crystalline body called serin, which appears to 
have the formula C3H7NO3, and from its chemical reactions is 
evidently analogous to glycocin, probably being amido- glyceric 
acid. 

Sericin is soluble in hot water, hot soap solutions, and dilute 
caustic alkalies. The aqueous solution is precipitated by alcohol, 
tannin, basic lead acetate, stannous chloride, bromine, and 
iodine, and by potassium ferrocyanide in the presence of acetic 
acid.f Mulder gives the formula of Ci5H25N50(j to sericin, and 
the following composition: 

Per Cent. 

Carbon 42 . 60 

Hydrogen 5-9° 

Oxygen 35 • 00 

Nitrogen 16. 50 

According to BoUey, the composition of sericin is: 

Per Cent. 

Carbon 44-32 

Hydrogen 6.18 

Oxygen 31 • 20 

Nitrogen 18 . 30 

* Pure sericin may also be prepared by precipitating crude sericin solution 
with I per cent, acetic acid, washing the separated sericin by repeated decante- 
tion with water, then treating with cold and afterwards with boiling alcohol, 
and finally extracting with ether. Pure sericin contains: 

C 45 ■ 00 per cent. 

H 6.32 " " 

N 17.14 " " 

31-54 " . " 

It is easily soluble in water, in concentrated hydrochloric acid, and in potas- 
sium carbonate; sodium carbonate only causes a swelling. 

t By treatment with formaldehyde it is claimed that sericin is rendered in- 
soluble in both hot water and soap solutions; consequently raw silk may be 
treated with this reagent for use in certain applications where it may be desired 
to retain as far as possible the coating of silk-glue. 



CHEMICAL NATURE AND PROPERTIES OF SILK. 91 

Vignon,* by observing the action of solutions of sericin and 
fibroin on polarized light, found that both of these constituents 
of silk were lasvogyrate, and their rotatory powers were about 
equal, approximating to 40°. This is in keeping with observa- 
tions made on other albuminoids. 

According to Dubois,! the yellow coloring-matter of silk is 
similar to carotin. He obtained five different bodies from the 
natural coloring-matter of silk, as follows: (i) a golden-yellow 
coloring-matter, soluble in potassium carbonate and precipitated 
by acetic acid; (2) crystals which appear yellowish red by trans- 
mitted light and brown by reflected light; (3) a lemon-colored 
amorphous body, the alcoholic solution of which on evaporation 
gave granular masses; (4) yellow octahedral crystals resembling 
sulphur; (5) a dark bluish green pigment in minute quantities 
and probably crystalline. 

2. Chemical Reactions. — In its general chemical behavior 
silk is quite similar to wool. It will stand a higher temperature, 
however, than the latter fibre, without receiving injury; it can 
be heated, for instance, to 110° C. without danger of decomposi- 
tion; at 170° C, however, it is rapidly disintegrated. On burning 
it liberates an empyreumatic odor which is not as disagreeable 
as that obtained from burning wool. Silk readily absorbs dilute 
acids from solutions, and in so doing increases in lustre and 
acquires the scroop of which mention has already been made. 
Unhke wool, it has a strong affinity for tannic acid, which fact 
is utilized for both weighting and mordanting the fibre. Silk 
also absorbs sugar to a considerable degree, and this substance 
may be employed as a weighting material for light-colored silks 
on ths account. Towards the ordinary metallic salts used as 
mordants silk exhibits quite an affinity; in fact, to such an extent 
can it absorb and fix certain metallic salts that silk material is 
frequently heavily mordanted with such salts for the purpose 
of unscrupulously increasing its weight. 

Solutions of sodium chloride appear to have a pecuUar action 
on the silk-fibre, especially in the presence of weighting materials. 

* Compt. rend., cxiii. 802. • f Ibid.^ cxi. 482. 



92 THE TEXTILE FIBRES. 

According to the researches of Sisley, solutions of common salt 
acting on weighted silk in the presence of air and moisture cause 
a complete destruction of the fibre in twelve months if charged 
with but 0.5 per cent, of salt; i per cent, of salt causes a very 
pronounced tendering of the fibre in two months, while 2 to 5 per 
cent, of salt causes a distinct tendering in seven days. The action 
of the salt is shared in a lesser degree by the chlorides of potassium, 
ammonium, magnesium, calcium, barium, aluminium, and zinc, 
and is probably due to chemical dissociation. This fact may 
account for the stains sometimes found in skeins of silk which 
also show a tendering of the fibre. These stains have frequently 
been noticed, and thorough investigation has failed to satisfactorily 
account for them. The salt may get into the fibre through the 
perspiration of the workmen handling the goods, or through a 
variety of other causes. 

Silk is not as sensitive to dilute alkalies as wool, though the 
lustre of the fibre is somewhat diminished.* When treated with 
strong hot alkalies the silk fibre dissolves. Ammonia and soaps 
have no effect on silk beyond dissolving off the silk-glue or seri- 
cin ; though on long- continued boiUng in soap, the fibroin is also 
attacked. Concentrated sulphuric f and hydrochloric acids dis- 
solve silk; nitric acid colors silk yellow, J as in the case with wool, 

* It is said that when mixed with glucose or glycerin caustic soda does not 
dissolve the silk fibre to any extent, but only removes the gum. 

t Though silk is soluble in concentrated acids if their action is continued 
for any length of time, it appears that if silk be treated with concentrated sul- 
phuric acid for only a few minutes, then rinsed and neutralized, the fibre will 
contract from 30 to 50 per cent, in length without otherwise suffering serious 
injury beyond a considerable loss in lustre. This action of concentrated acids on 
silk has been utilized for the creping of silk fabrics, the acid being allowed to act 
only on certain parts of the material. It appears that tussah silk is not affected 
by the acid to the same degree as ordinary silk, and hence creping may be 
accompUshed by mixing tussah with ordinary silk, and treating the entire fabric 
with concentrated acid. 

% The action of nitric acid on silk is rather a peculiar one. When treated 
for one minute with nitric acid of sp. gr. 1.33 at a temperature of 45° C, the silk 
.acquires a yellow color which cannot be washed out and is also fast to light. Pure 
nitric acid free from nitrous compounds, however, does not give this color. On 
treating the yellow nitro-silk with an alkali the color is considerably deepened. 
With strong sulphuric acid nitro-silk swells up and gives a gelatinous mass re- 
sembling egg albimiin. 



CHEMICAL NATURE AND PROPERTIES OF SILK. 93 

probably due to the formation of xanthroproteic acid. This 
color can be removed by treatment with a boiling solution of 
stannous chloride. A concentrated solution of basic zinc chlo- 
ride readily dissolves the silk fibre.* An acid solution of zinc 
chloride also acts in the same manner. Solutions of copper 
oxide or nickel oxide in ammonia also act as solvents towards 
silk. The latter solution can be employed for separating silk 
from cotton, the silk being readily and completely soluble in a 
boiling solution of ammoniacal nickel oxide, whereas cotton loses 
less than i per cent, of its weight. A boiling solution of basic 
zinc chloride (1:1) will dissolve silk in one minute, while cotton 
under the same treatment loses only 0.5 per cent., and wool only 
1.5 to 2 per cent.f Chlorine destroys silk, as do othef oxidizing 
agents, unless employed in very dilute solutions and with great 
care. 

Hydrofiuosilicic acid and hydrofluoric acid in the cold and in 
5 per cent, solutions do not appear to exert any injurious action 
on the silk- fib re; these acids, however, remove all inorganic 
weighting materials, and their use has been suggested for the 
restoring of excessively weighted silks to their normal condition, 
so that they may be less harsh and brittle. 

Towards coloring-matters in general, silk exhibits a greater 
capacity of absorption than perhaps any other fibre. It also 
absorbs dyestuffs at much lower temperatures than does wool. 

3. Tussah Silk presents a number of differences, both physi- 
cally and chemically, from ordinary silk. It has a brown color 
and is considerably stiffer and coarser. It is less reactive, in 
general, towards chemical reagents, and consequently presents 



* On diluting this solution with water a flocculent precipitate is obtained 
which is soluble in ammonia, and the latter solution has been employed for coat- 
ing vegetable fibres with silk for the production of certain so-called "artificial 
silks." 

t Silk is also soluble in Schweitzer's reagent (cupro-ammonium hydrate), and 
in an alkaline solution of copper sulphate and glycerin. The latter is used to 
separate silk from wool and cotton; and the following solution is recommended: 
16 grams copper sulphate, 10 granls glycerin, and 150 c.c. of water. After dis- 
solving, add a solution of caustic soda, until the precipitate which at first forms 
is just redissolved. 



94 THE TEXTILE FIBRES. 

more difficulty in bleaching and dyeing. Tussah silk requires 
a much more severe treatment for ungumming than cultivated 
silk, and the boiled-off liquor so obtained is of no value in dyeing. 
According to analyses of Bastow and Appleyard* raw tus- 
sah silk gives the following results: 

Per Cent. 

Soluble in hot water 21 . 33 

Dissolved by alcohol (fatty acid) 0.91 

Dissolved by ether o . 08 

Total loss on boiling off with i per cent, solution 

of soap 26 . 49 

Mineral matter 5-34 

These same observers consider that the fibroin of tussah silk 
differs chemically from that of ordinary silk, as it is much less 
readily acted on by solvents. In order to obtain pure tussah 
fibroin the silk should be boiled repeatedly with a i per cent, 
solution of soap, washed with water, extracted with hydrochloric 
acid; and after again washing with water and drying, extracted 
successively with alcohol and ether. Tussah fibroin purified in 
this manner shows the following composition: 

Per Cent. 

Carbon 47 • 18 

Hydrogen 6.30 

Nitrogen 16 . 85 

Oxygen 29 . 67 

These figures are exclusive of 0.226 per cent, of ash. Apple- 
yard gives the following analysis of the ash from raw tussah 
silk: 

Per Cent. 

Soda, NajO 12.45 

Potash, K2O 31 . 68 

Alumina, AI2O3 i . 46 

Lime, CaO 13 • 32 

Magnesia, MgO 2 . 56 

Phosphoric acid, P2O5 6 . 90 

Carbonic acid, COj 1 1 . 14 

Silica, SiOz 9 . 79 

Hydrochloric acid, CI 2 . 89 

■ Sulphuric acid, SO3 8.16 

* Jour. Soc. Dyers' and Col., iv. 88. 



CHEMICAL NATURE AND PROPERTIES OF SILK. 



95 



The presence of sulphates in this ash is somewhat remark- 
able, as this constituent does not occur in ordinary silk. The 
occurrence of alumina is also remarkable, as this element is sel- 
dom a constituent of animal tissues. As the amount of ash of 
purified fibroin of both common silk and tussah silk is very 
much lower than that of the raw silks, it is to be considered prob- 
able that most of the mineral matter found is derived from adher- 
ing impurities, and is not a true constituent of the silk itself. 

Tussah silk is scarcely affected by an alkaline solution of 
copper hydrate in glycerin, whereas ordinary silk is readily 
soluble in this reagent.* 

The following table exhibits the principal differences between 
true silk and tussah silk:"}" 



Reagent. 


True Silk. 


i Tussah Silk. 


Hot caustic soda (io%) 


Dissolves in 12 minutes 


Requires 50 minutes for 
solution 


Cold hydrochloric acid (sp. 


Dissolves verj' rapidly 


Only partially dissolves 


gr. i-i6) 




in 48 hours 


Cold cone, nitric acid 


Dissolves in 5 minutes 


Dissolves in 10 minutes 


Neutral solution of zinc chlo- 


Dissolves very rapidly 


Dissolves but slowly 


ride (sp. gr. 1.725) 






Strong chromic acid solution 


Dissolves very rapidly 


Dissolves very slowly 


in water 







While the fibre of true silk presents the appearance of a 
structureless thread, and rarely exhibits signs of distinct striation, 
tussah (and other ' ' wild ' ' silks) is made up of bundles of delicate 
fibrillae, varying in diameter from 0.0003 to 0.0015 mm., so that 
the fibre as a whole presents a striated appearance. Also the 
cross-section | of tussah silk is considerably larger than that 
of true silk, and is more flattened; it also exhibits numerous 
fine air-tubes. The following table exhibits the difference in 
the microscopic appearance of various kinds of raw silk; the 
diameter is expressed in ^ = thousandths of a millimeter : § 



* Filsinger, Chem. Zeit., xx. 324. 

t Bastow and Appleyard, Jour. Soc. Dyers' and Col., rv'. 89. 

X Filsinger, vide supra. 

§ Hohnel, Jour. Soc. CJiem. Ind., II. 172. 



96 



THE TEXTILE FIBRES. 







Appearance. 


Variety of Silk. 


T^isiTiGtcr 






Broad Side. 


Narrow Side. 


True silk, Bomhyx 


20 to 25 


White or yellowish; 


White or yellowish; 


mori 




shiny 


Shiny 


Senegal silk, B. 


30 to 35 


Shining yellowish or 


Gray, brown, or black, 


faidherbi 




brownish white, or 


with occasionally 






pale yellow, gray. 


hghter shades 






brown, and occasion- 








ally bluish white 




Ailanthus silk, B. 


40 to 50 


Shining yellowish white. 


Dirty gray or brown to 


cynthia 




with yellow, brown, or 


black, with green, yel- 






brownish-gray spots 


low, red; violet, or blue 

spots 


Yama-mai silk, 


40 to 50 


Bluish white with dark 


Glaring and fine colors, 


Anther csa yama- 




blue, blue and black 


with dark or black 


mai 




shades 


shades 


Tussah silk, Actius 


50 to 55 


Irregular in thickness. 


Dark gray, with pink or 


selene 




Thickest parts with 
gray and blue spots; 
thinner parts b uish 
white, yellow, or 
orange-red 


Hght green spots 


Tussah silk, An^ 


60 to 65 


Similar to above, but 


Similar to above 


thercBa mylitta 




spots orange-red, red, 
or brown 





CHAPTER VIII. 

THE VEGETABLE FIBRES. 

I. The basis of all vegetable fibres is to be found in cellulose, 
a compound belonging to a class of naturally occurring sub- 
stances known as carbohydrates. The fibres may be either 
seed-hairs, such as the different varieties of cotton, cotton-silk, 
etc.; or bast fibres, which include those obtained from the cam- 
bium layer of the dicotyledonous plants, such as flax, hemp, 
jute, ramie, etc. ; or vascular fibres, which include those obtained 
chiefly from the leaf-tissues of the monocotyledonous plants, 
such as phormium, agave, aloe, etc.* 

Anatomically considered, the plant fibres may be divided into 
six dift'erent classes (Hohnel) : 

(i) Single-cell plant-hairs, such as cotton, vegetable silk, and 
vegetable down. 

(2) Fibres consisting of several cells, such as pulu fibre, 
elephant- grass, and cotton-grass. 

(3) Bast fibres, such as flax, hemp, jute, ramie, etc. 

(4) Dicotyledonous bast fibres, such as Hnden-bast, Cuba 
bast, etc. 

(5) Monocotyledonous vascular fibres, such as sisal hemp, 
aloe-hemp, pineapple fibre, cocoanut fibre, etc. 

* There is a peculiar instance in which the entire plant is used as the fibre; 
this is sea-grass or sea-wrack (Zostera marina). However, it can scarcely be 
considered as a textile fibre, as it is almost altogether employed for stuffing and 
packing. 

97 



98 THE TEXTILE FIBRES. 

(6) Monocotyledonous schlerenchymous fibres, such as 
Manila hemp, New Zealand flax, etc. 

There is considerable difference to be observed between the 
anatomical structure of seed-hairs and that of bast fibres. Seed- 
hairs are known botanically as plumose fibres, and consist of a 
unicellular fibre or trichrome, exhibiting only a single solid apex, 
the other end being attached to the seed. Externally they 
appear to be covered with a thin skin or cuticle which differs 
essentially from the remaining cellulose in that it is not dissolved 
by treatment with sulphuric acid. The cell-walls vary con- 
siderably in their thickness, and are structureless and porous. 
Through the centre of the fibre runs a hollow canal, called the 
lumen, the chief content of which appears to be air. Usually 
the dried fibre is flattened into the form of a band, and the lumen 
then becomes almost nothing. Bast fibres, on the other hand, 
consist of completely enclosed tubes, each end being pointed. 
Each individual fibre is multicellular, the cells being long and 
usually polygonal in cross-section. The cell-walls are usually 
rather thick, and the cross- section instead of being flat and narrow 
is broad and more or less rounded. The inner wall is frequently 
covered with a thin layer of dried protoplasm. One of the most 
characteristic appearances of the bast fibres is the occurrence 
of dislocations or joints throughout the length of the fibre. These 
dislocations also show the property of becoming more deeply 
colored than the rest of the fibre when treated with a solution 
of chlor-iodide of zinc. These knots or joints generally show 
thicker overlying transverse fissures, between which lie small 
short discs arranged on edge. The joints disappear altogether 
in the monocotyledonous fibres; they are also lacking on many 
true bast fibres, such as jute, linden-bast, etc., but occur in hemp, 
flax, ramie, etc. " : 

Bast fibres are the long, tough cells found in the bark and 
stem of various plants. The cell- walls of these fibres are usually 
partially changed-from-pure cellulose into lignin and are thickened. 
There is usually a considerable amount of foreign matter also 
contained in the cell- wall, and often this becomes sufficiently 
characteristic to serve as a means of* identifying the various 



THE VEGET/IBLE FIBRES. 



99 



fibres by the application of chemical reagents. Unlike seed- 
hairs, the individual cells of bast fibres are not of sufficient length 
for use in spinning, but as they are held together with considerable 
firmness to form bundles of great length, they are utilized in this 
form. 

Wiesner gives the following table showing the length of the 
raw fibre and the dimensions of the cells composing them: 



Fibre 



' Length of 
I Raw Fibre, 



Length of 
Cells, 
mm. 



Breadth of Cells. 



Min. /I. I Max. /(.jAver. ;i 



Tillandsia fibre ! 2-22 

Esparto grass ! 10-40 

Cordia latijolia I 50— qo 

80-110 
60-70 

50-150 

150-300 

100-180 

100—120 

80-100 

20-30 

40-50 

20-140 



Phormium tenax 
Abelmochus tetraphyllos.. . . 

Bauhinia racemosa 

Jute (Corchorus capsularis). 

Thespesia lam pas 

Urena sinuala 

Sida retusa 

Calotropis gigantea (bast) . . 

Aloe perjoliata 

Fla.x (Linitm usitatissimiim) 

Hemp {Cannabis saliva) j 100-300 

Jute {Corchorus olitoriiis) ' 150-300 

Hibiscus cannabinus I 40-90 

Sunn {Crotolaria juticea) | 20-50 

Bromelia karatas ' loo-i 10 

China grass {Bolimeria nivea.) ! 

Ramie {Bolimeria tenacissima) 



Cotton {Gossypium barbadense) 

do. {G. conglomeratum) 

do. {G. herbaceiim) 

do. {G. acuminatum) 

do. {G. arborcum) 

Cotton wool {Bombax heptaphyllum) 
Vegetable silk {Calotropis gigantea). 



{AsclepUis). 
{Marsdenia). . . 
{Strophanthus). 
{Beaumontia). . 



do. 

do. 

do. 

do. 
Linden-bast 

Slerculia villosa 

Holoptelia inlegri folia. . 

Kydia calyciim 

Lasoisyphon speciosus. . 

Sponia wightii 

Pandanus odoratissimus. 

Pita fibre 

Coir fibre 



4-05 

3-51 

1.82 

2.84 

2.50 

2r3 

2-3 



o . 2-0 . 5 
I. 5-1. 9 
o. i-i .6 
2.5-5.6 
o. i-i .6 
I . 5-4 . o 
0.8-4.1 
0.9-4.7 
I . 1-3 . 2 
0.8-2. 3 
0.7-3.0 

I • 3-3 ■ 7 
2 . 0-4 . o 
o . 8-4 . I 

0.8-4.1 

4.0-12.0 

0.5-6.9 
1.4-6.7 

22.0 

8.0 

40.5 

35-1 

18.2 

28.4 

25.0 

20-30 

20-30 

10-30 

10-25 

10-56 

30-45 
I . 1-2.6 

I ■ 5-3 ■ 5 

0.9-2. I 

1-2 

0.4-5.1 

4 
I . 0-4 . 2 
I . 0-2 . 2 
o . 4-0 . 9 



6 

9 

14. 
8 
8 
8 



12 
16 
16 
20 
20 
27 
40 
16 
19.2 

17 

II. 9 
20. 1 
20 

19 
12 
20 
19 
49 
33 



17 

9 

17 



16 

12 



16.8 

29 



24 



24 

25 

32 

3^ 

41 

42 

42 

80 

12 . 6 

27.9 



29.9 

37-S 

29 

42 

44 

33 

92 

50 



13 
16 



16 
16 



16 
20 
20 



50 



25-5 
18.9 
29.4 
29.9 



3^ 



15 



L.of 



THE TEXTILE FIBRES. 



Vetillard gives a somewhat similar table as follows : 



Name. 



Linen 

Hemp {Cannabis sativa) 

Hop fibre {Humulus liipulus) 

Nettle fibre ( Uriica dioica) 

Ramie {Urtica nivea) 

Fibre of paper mulberry 

Sunn hemp (Crotalaria junced) 

Broom-grass {Sarothamnus vulgario) . 
Feather-grass {Spartium funceum) .... 

Meliotus alba 

Cotton 

Gambo hemp {Hisbiscus cannabinus) 

Linden-bast (Tilia europaa) 

Jute {Corchorus capsularis) 

Lagetta lintearia 

Salix alba 

Esparto 

Lygceum spartum 

Pineapple fibre 

Bromelia karatas 

Bromelia pinguin 

Phormium tenax (New Zealand flax) . . 

Yucca fibre 

Sanseveria fibre 

Agave americana 

Musa textilis (Manila hemp) 

Musa paradisaica 

Phcenix dactylifera 

Corypha umbraculijera 

Elais giiineensis 

Raphia taetigera 

Mauritia flexuosa 

Coir fibre (Cocas uncifera) 



Length (in mm.). I Breadth (in /i). 



Min. Max. Mean.' Min. Max. Mean 



I-S 



o-S 
1-3 
3 

2-5 

0.8 

5 

0-5 

i-S 

1-5 

3 



66 

55 
19 

57 
250 

25 
12 

9 

16 
18 
40 
6 
5 
5 
6 

3 
3- 
4- 
9 



1-5 
1-5 
1-5 

I 
0.4 



2-5 

15 
6 
6 



25 

20 

ID 

27 
120 



1-5 

2-5 

5 



9 
4 
3 

2-5 



5 
3 
3 

2-5 
2-5 

1-5 
0.7 



25 



14 
14 
20 
10 
17 
7 
12 

4 
20 



15 
20 
16 
20 
16 
16 



37 
50 
26 
70 



50 
25 



36 

33 
20 

25 
20 

30 



32 
16 
20 
20 
26 
32 
32 
40 
24 
28 

13 
20 
16 

24 



20 
22 
16 
50 
50 
30 
30 
15 

'20 
30 

21 

16 

22.5 



15 

6 
24 

13 
16 

IS 
20 

24 
24 
28 
20 

24 
II 
16 



°^s 



'm 



1200 

1000 

620 

550 
2400 

350 
260 

330 
500 

330 

240 

125 
90 

500 
90 

125 
160 
830 
210 
150 
550 
170 

150 
100 
250 
180 
150 
120 
230 
160 
130 
35 



2. Classification. — Perhaps the most systematic and complete 
enumeration of the various vegetable fibres, together with a 
classification of their technical uses, is that given by Dodge in 
his "Report on the Useful Plant Fibres of the World," from which 
the following abstract is taken: 



STRUCTURAL CLASSIFICATION. 
A. FiBROVASCULAR STRUCTURE. 

I. Bast fibres. — Derived from the inner fibrous bark of dicot- 
yledonous plants or exogens, or outside growers. They are 



THE l^EGET/^BLE FIBRES. loi 

composed of bast-cells, the ends of which overlap each other, so as 
to form in mass a filament. They occupy the phloem portion 
of the fibrovascular bundles, and their utility in nature is to give 
strength and flexibility to the tissue. 

2. Woody fibres. 

(a) The stems and twigs of exogenous plants, simply 
stripped of their bark and used entire, or Separated into withes 
for weaving or plaiting into basketry. 

(b) The entire or subdivided roots of exogenous plants, 
to be employed for the same purpose, or as tie material, or as 
very coarse thread for stitching or binding. 

(c) The wood of exogenous trees easily divisible into 
layers or splints for the same purposes, or more finely divided into 
thread-like shavings for packing material. 

(d) The wood of certain soft species of exogenous trees, 
after grinding and converting by chemical means into wood- 
pulp, which is simple cellulose, and similar woods more carefully 
prepared for the manufacture of artificial silk. 

3. Structural fibres. 

(a) Derived from the structural system of the stalks, leaf- 
stems, and leaves, or other parts of monocotyledonous plants, 
or inside growers, occurring as isolated fibrovascular bundles, 
and surrounded by a pithy, spongy, corky, or often a soft, succu- 
lent, cellular mass covered with a thick epidermis. They give 
to the plant rigidity and toughness, thus enabling it to resist 
injury from the elements, and they also serve as water-vessels. 

(b) The whole stems, or roots, or leaves, or split and 
shredded leaves of monocotyledonous plants. 

(c) The fibrous portion of the leaves or fruits of certain 
exogenous plants when deprived of their epidermis and soft 
cellular tissue. 

B. Simple Cellular Structure. 

4. Surjace fibres. 

(a) The down or hairs surrounding the seeds, or seed 
envelopes, of exogenous plants, which are usually contained in 
a husk, pod, or capsule. 



I0 2 THE TEXTILE FIBRES. 

(b) Hair-like growths, or tomentum, found on the surfaces 
of stems and leaves, or on the leaf-buds of both divisions of plants. 

(f) The fibrous material produced in the form of epi- 
dermal strips from the leaves of certain endogenous species, as 
the palms. 

5. Pseudo- fibres, or false fibrous material. 

(a) Certain of the mosses, as the species of the sphagnum, 
for packing material. 

(b) Certain leaves 'and marine weeds, the dried substance 
of which forms a more delicate packing material. 

(c) Seaweeds wrought into lines and cordage. 

(d) Fungous growths, or the mycelium of certain fungi 
that may be applied to economic uses, for which some of the 
true fibres are employed. 

The bast fibres are clearly defined, and all such fibres when 
simply s ripped are similar in form as to outward appearance, 
differing chiefly in color, fineness, and strength. An example 
of a fine bast fibre is the ribbons or filaments of hemp. The 
woody fibres are only fibrous in the broad sense, as their cellulose 
is broken down and all extraneous matter removed by chemical 
means, as for the manufacture of paper-pulp or of artificial silk. 
The structural fibres are found in many forms differing widely 
from each other, and the surface fibres are still more varied in 
form. 

ECONOMIC CLASSIFICATION. 

A. Spinning Fibres. 

I. Fabric fibres. 

(a) Fibres of the first rank for spinning and weaving into 
fine and coarse textures for wearing apparel, domestic use, or 
house furnishing and decoration, and for awnings, sails, etc. 
(The commercial forms are cotton, flax, ramie, hemp, pineapple, 
and New Zealand flax.) 

(b) Fibres of the second rank, used for burlap or gunny, 
cotton bagging, woven mattings, floor coverings, and other coarse 
uses. (Commercial examples are coir and jute.) 



THE y EG STABLE FIBRES. 103 

2. Netting fibres. 

(a) Lace fibres, which are cotton, flax, ramie, agave, etc. 

(b) Coarse netting fibres, for all forms of nets, and for 
hammocks. (Commercial forms: Cotton, flax, ramie, New- 
Zealand flax, agave, etc.) 

3. Cordage fibres. 

(a) Fine spun threads and yams other than for weaving; 
cords, lines, and twines. (All of the commercial fabric fibres, 
sunn, Mauritius, and bowstring hemps, New Zealand flax, coir, 
Manila, sisal hemps; the fish- lines made from seaweeds.) 

(b) Ropes and cables. (Chiefly common hemp, sisal and 
Manila hemps, when produced commercially.) 

B. Tie ^Iaterial (rough twisted). 

Very coarse material, such as stripped palm-leaves, the peeled 
bark of trees, and other coarse growths used without preparation. 

C. Natural Textures. 

1. Tree-basts, with tough interlacing fibres. 

(a) Substitutes for cloth, prepared by simple stripping 
and pounding. 

(b) Lace-barks, used for cravats, frills, ruffles, etc., and for 
whips and thongs. 

2. The ribbon or layer basts, extracted in thin, smooth- sur- 
faced, flexible strips or sheets. (Cuba bast used as millinery 
material, cigarette wrappers, etc.) 

3. Interlacing structural fibre or sheaths. 

(a) Pertaining to leaves and leaf- stems of palms, such as 
the fibrous sheaths found at the bases of the leaf-stalks of the 
cocoanut. 

(&) Pertaining to flower-buds. The natural caps or hats 
derived from several species of palms. 

D. Brush Fibres. 

I. Brushes manufactured from prepared fibre. 

(a) For soft brushes. (Substitutes for animal bristles, 
such as Tampico.) 



I04 THE TEXTILE FIBRES. 

(h) For hard brushes. (Examples: Palmetto fibre, pal- 
myra, kittul, etc.) 

2. Brooms and whisks. 

{a) Grass- like fibres. (Examples : Broom- root, broom- 
corii, etc.) ; 

(h) Bass fibres. (Monkey basSj etc.) 

3. Very coarse brushes and brooms. 

Material used in street cleaning. Usually twigs and splints. 

E. Plaiting and Rough-weaving Fibres. 

1. Used in hats, sandals, etc. 

(a) Straw-plaits. From wheat, rye, barley, and rice- 
straw. (Tuscan and Japanese braids.) 

(b) Plaits from split leaves, chiefly palms and allied forms 
of vegetation. (Panama hats.) 

(c) Plaits from various materials. (Bast and thin woods 
used in millinery trimmings.) 

2. Mats and mattings; also thatch materials. 

(a) Commercial mattings from Eastern countries. 
(&) Sleeping-mats, screens, etc. 

(c) Thatch-roofs, made from tree-basts, palm-leaves, 
grasses, etc. 

3. Basketry. 

(a) Manufactures from woody fibre. 

(b) From whole or split leaves or stems. 

4. Miscellaneous manufactures. 

Willow- ware in various forms; chair-bottoms, etc., from 
splints or rushes. 

F. Various Forms oe Filling. 

I. Stuifing or Upholstery. 

(a) Wadding, batting, etc., usually commercially pre- 
pared lint-cotton. 

(b) Feather substitutes for filhng cushions, etc.; cotton, 
seed-hairs, tomentum from surfaces of leaves, other soft fibrous 
material. 

(c) Mattress and furniture filhng. The tow or waste of 



THE VEGETABLE FIBRES. 105 

prepared fibre; unprepared bast, straw, and grasses; Spanish 
moss, etc. 

2. Caulking. 

(a) Filling the seams in vessels, etc. ; oakum from various 
fibres. 

(b) Filling the seams in casks, etc.; leaves of reeds and 
giant grasses. 

3. Stiffening. 

In the manufacture of "staff" for building purposes, and 
as substitutes for cow-hair in plaster. New Zealand flax; pal- 
metto fibre. 

4. Packing. 

(a) In bulkheads, etc. Coir, cellulose of corn- pith. In 
machinery, as in valves of steam-engines; various soft fibres. 

(b) For protection in transportation; various fibres and 
soft grasses; marine weeds; excelsior. 

G. Paper Material. 

1. Textile papers. 

(a) The spinning fibres in the raw state; the secondary 
qualities or waste from spinning mills, which may be used for 
paper stock, including tow, jute-butts, Manila rope, etc. 

(b) Cotton or flax fibres that has already been spun and 
woven, but which, as rags, finds use as a paper material. 

2. Bast papers. 

This includes Japanese papers from soft basts, such as 
the paper mulberry. 

3. Palm papers. 

From the fibrous material of palms and similar plants. 
Palmetto and Yucca papers. 

4. Bamboo and grass papers. 

This includes all paper material from gramineous plants, 
including the bamboos, esparto, etc. 

5. Wood-pulp, or cellulose. 

The wood of spruce, poplar, and similar "paper- pulp" 
woods prepared by various chemical and mechanical processes. 



io6 THE TEXTILE FIBRES. 

3. Physical Structure and Properties. — Seed-hairs, or plumose 
fibres, are divided into thiee morphological classes: 

(i) Those consisting of single cells, one end of which is 
closed and tapers to a point, the other end being broken off 
abruptly where it is torn from the seed to which it was fastened 
during growth. This class includes the most important plumose 
fibres, such as cotton and the vegetable silks. 

(2) Those consisting of a series of cells joined together to 
form a continuous fibre; this class includes the tomentum or 
epidermal hair obtained from certain ferns, and are practically 
valuless as textile materials, though used for upholstery and such 
purposes. 

(3) Those consisting of several series of cells, represented 
by the fibres of the so-called cotton-grass and elephant- grass. 

The cell-wall of the plumose fibres in some cases is relatively 
thin, while in others it is comparatively thick. It is generally 
without apparent structure, though sometimes it is seen to con- 
tain pores, and occasionally a mesh-like interlacing of filaments 
is observable, especially at the base of the fibre. The inner 
surface of the cell-wall is usually coated with a cuticule of 
dried protoplasm, which is evidently similar in constitution to 
the outer cuticule, as it also remains undissolved when the fibre 
is dissolved in either concentrated sulphuric acid or an ammo- 
niacal solution of copper oxide. The general term of the bast 
fibre includes really two distinct forms; if the fibre occurs in 
the bast itself it should be designated as true hast fibres, such as 
linen, hemp, and jute. When, however the fibres occur not in 
the bast, but in single bundles in the leaf structure of the plant, 
they should be designated as sclerenchymous fibres. In true bast 
fibres there are seldom to be noticed distinct pores, whereas 
the sclerenchymous fibres are abundantly supplied with them. 
On the other hand, however, the true bast fibres frequently 
show peculiar dislocations or joints caused by an unequal cell- 
pressure in the growing plant; these are entirely absent in the 
sclerenchymous fibres. The ends of all bast fibres are usually 
quite characteristic and exhibit a wide diversity of forms; at 
times they are sharp-pointed and again blunt; some possess 



THE yE GET ABLE FIBRES. 107 

but a single point, while others are split or forKed; sometimes 
the cell-wall is thicker than in the rest of the fibre, and sometimes 
it is thinner. When the cells occur in bundles they are frequently 
separated from one another by a so-called median layer, which 
forms a sort of matrix in which the separate filaments are imbedded. 
This layer usually differs in its chemical composition from the 
cell-wall proper, and gives different color reactions with various 
reagents, as it generally consists of lignified tissue. In many 
cases the cell-walls appear to have a distinct structure, being 
composed of concentric layers which in cross-section exhibit a 
stratified appearance. 

Although cellulose forms the chief constituent of all vegetable 
fibres, it varies much in its purity and associated products in 
its occurrence in the various fibres. Seed-hairs like cotton con- 
sist almost entirely of cellulose in a rather pure state, but the 
bast and vascular fibres always contain more or less alteration 
products of cellulose, chief among which is ligno- cellulose or 
lignin; in fact, jute is almost entirely composed of this latter 
substance. Seed-hairs consist of one single cell to the individual 
fibre and have very little foreign or incrusting material present. 
The other fibres are made up of an aggregation of cells bound 
together in a compact form, and in the cell interstices there is 
always present more or less gummy and resinous matter, oils, 
mineral matter, and lignified tissue. All vegetable fibres appear 
to contain more or less pigment matter, usually of a slight yellowish 
or brownish color. In ordinary cotton and ramie this coloring- 
matter occurs in only a very small amount and the natural fibre 
is quite white in appearance. There are some varieties of cotton, 
however, which are distinctly brown in color. Flax, jute, hemp, 
etc., contain a considerable amount of pigment and are of a 
brownish color more or less pronounced. 

Besides cellulose and lignin, there is also present, especially in 
seed-hairs, a cutose membrane (cork-tissue) in the form of an 
external cuticle. Cutose is very insoluble in concentrated sul- 
phuric acid, but is partially soluble in boiling potash. It doubt- 
less originates from the plant-wax which is imbedded in the cell. 
Albuminous matter also occurs in the fibre elements, mostly as a 



lo8 THE TEXTILE FIBRES. 

dried tissue which fills the lumen of the fibre more or less com- 
pletely. It also occurs as a thin film which coats the inner wall 
of the cell, and remains undissolved when the fibre is treated with 
concentrated sulphuric acid. This membrane exhibits all the 
reactions of albumin. Silicic acid sometimes is present in vege- 
table fibres, but only in the walls of the stegmata and in epidermal 
cells. On ignition the silicious matter is left in almost the 
original form of the fibre. The silicious skeleton is insoluble in 
hydrochloric acid, whereas the rest of the ash is readily dissolved 
by this reagent. Crystals of calcium oxalate occasionally occur 
in some fibres; they are insoluble in acetic but dissolve in hydro- 
chloric acid. On ignition of the fibres these crystals are con- 
verted into calcium carbonate without much change of form, and 
then are soluble in even very dilute acids. 

All plant- cell membranes are doubly refractive towards light, 
and this is especially true of thick-walled cells which are parallel 
to the fibre proper. If such a fibre is examined in the dark field 
of a micro-polariscope it shows a beautiful arrangement of bright 
prismatic colors. 

In color the vegetable fibres vary considerably in the raw state; 
some, hke cotton, ramie, and the vegetable silks, are almost 
pure white. Others, hke linen, possess a grayish brown color; 
while others yet, like jute and hemp, have a decided broviTi color. 
These colors, however, are due to incrusting impurities, as the 
cellulose fibres, purified and freed from all such foreign matters, 
are always white. 

In lustre the vegetable fibres are usually below those of animal 
origin, and especially silk, though they differ much in this respect. 
Cotton probably has the least lustre of any, as its external surface 
is by no means smooth and even, but presents a wrinkled and 
creased appearance, hence scatters the rays of light reflected 
therefrom. The other plumose fibres, as the various vegetable 
silks, have a very smooth surface, and consequently exhibit 
considerable lustre. Linen, jute, ramie, and the bast fibres in 
general, when decorticated to their fine filaments, and properly 
freed from all incrusting matter, possess a rather high degree of 
lustre; for though they have more or less roughened places and 



THE J^EGETABLE FIBRES. 



109 



irregularities on their external surface, the majority of such 
surface is smooth and regular. 

The more closely the fibre approximates to pure cellulose, 
the greater becomes its -jlexibility and elasticity; and the more it is 
lignified the less these quaHties become. That is to say, the 
highly lignified fibres are stiff and brittle, and but Httle adapted 
to the spinning of fine yarns. 

The hygroscopic moisture contained in vegetable fibres is 
considerably lower than that present in either wool or silk. While 
the latter fibres under normal atmospheric conditions will aver- 
age as much as 12 to 18 per cent, of moisture, cotton and linen will 
have only from 6 to 8 per cent. The following table (after Wies- 
ner) gives the amount of moisture in various vegetable fibres 
in the ordinary air-dry condition, and also the greatest amount 
they will absorb hygroscopically : 

HYGROSCOPIC MOISTURE IN VEGETABLE FIBRES. 



Fibre. 



Air-dry 
Condition. 



Maximum 

Amount 

Hygroscopic 

Water. 



Cotton 

Flax (Belgian) 

Jute 

China grass 

Manila hemp 

Sunn hemp 

Hibiscus cannabinus . . . , 
Abelmoschus tetraphyllos. . 

Esparto 

Urena sinuata 

Piassave 

Sida retusa 

Aloe perfoliata 

Bromelia karatas 

Tliespesia lampas , 

Cordia lati folia 

Bauhinia racentosa 

Tillandsia fibre 

Pita 

Calotropio gigantea (bast) 



6.66 

5-7° 
6.00 
6.52 
12.50 
5-31 
7-38 
6.80 

6-95 
7.02 
9.26 
7-49 
6-95 
6.82 
10.83 

8-93 
7.84 
9.00 
12.30 
5-67 



20.99 
13.90 

23-30 
18. IS 
40.00 
10.87 
14.61 
13.00 
1332 
15.20 
16.98 
17. II 
18.03 
18.19 
18.19 
18.22 
19. 12 
20.50 
30.00 
13- 13 



CHAPTER IX. 

COTTON, 

I. Origin and Growth. — The use of cotton as a textile fibre 
dates back to antiquity, mention of it being found in the writings 
of Herodotus (445 B.C.). It was used in India, Egypt, and China. 
The first European country to make cotton goods appears to 
have been Spain. 

The cotton fibre consists of the seed-hairs of several species 
of the genus Gossypium, belonging to the natural order of Mai- 
vacecB. 

The cotton plant is a shrub which reaches the height of 4 to 
6 ft. It is more or less indigenous to nearly all sub-tropical 
countries, though it appears to be best capable of cultivation in 
warm, humid climates where the soil is sandy, and in the neighbor- 
hood of the sea, lakes, or large rivers. It appears to thrive most 
readily in North and South America, India, and Egypt; it has 
also been cultivated in Australia, but not as yet with any great 
degree of success; inferior qualities have been grown along the 
coasts of Africa; that grown in Europe (Italy and Spain) is prac- 
tically negligible, as far as commercial considerations are con- 
cerned. In America, India, and Egypt the cotton plant is annual 
in its growth, but in hot tropical climates, and in South America, 
it becomes a perennial plant, and assumes more of a tree-like 
form. The leaf of the cotton plant has three- pointed lobes; 
the flower has five petals, yellow at the base, but becoming almost 
white at the edges. The fruit of the cotton plant forms the cotton 
boll, which contains the seeds with the attached fibres. The 
boll consists of from three to five segments, and on ripening 



COTTON. Ill 

bursts open and discloses a mass of pearly white downy fibres 
(Fig. 30), in which are imbedded the brownish black to black- 
colored cottonseeds. The cotton boll should be picked as soon 
as possible after ripening; the seeds are then separated from the 
fibres by a process known as ginning. Besides the fibre itself, 
nearly all of the other products of the cotton are now utilized 
commercially. The seeds are of especial value, as they contain a 





Fig. 30. — Sections of the Cotton Boll (Egyptian). (Witt.) 
A, stem; B, calyx; C, capsule; D, seed; E, cotton fibre. 

large quantity of oil, which is expressed and used for soap-making 
and many other purposes, while the residuum of meal and hulls 
is converted into cattle foods and fertilizer. The short fibres, 
or nep, left on the seed after the first ginning, are also recovered 
by a second process and used in the manufacture of lint and 
cotton-batting. The separation of seed particles from the fibre 
is not always perfect, and they frequently make their appearance 
in gray calico in the form of black specks or motes, and as these 



112 



THE TEXTILE FIBRES. 



contain small quantities of oil and tannin matters which are pressed 
out into the surrounding fibres, they cause specks and uneven- 
ness in dyeing and finishing. If they come in contact with solu- 
tions or materials containing iron compounds, a violet stain will 
be produced, the color of which, however, may not develop for 
some months. 

Bowman {loc. cit.) gives an excellent description of the 
physiological development of the cotton fibre, from which the 
following is quoted: "In their earhest stages the young cotton 




Fig. 31. — Typical Cotton Fibres. 
A, normal fibre showing regular twists; B, straight fibre without twists; 
C, a knot or irregularity in growth of fibre. 

fibres appear to have a circular section arising from the com- 
parative thickness of the tube- walls; but as these walls gradually 
become thinner by the longitudinal growth of the hair and the 
pressure to which they are subjected by the contact of surround- 
ing fibres enclosed within the pod, they gradually become flat- 
tened, and just before the pod bursts the outer walls of the cells 
have become so attenuated in the longest fibres as to be almost 
invisible even under high microscopic powers, and present the 
appearance of a thin, pellucid, transparent ribbon. With the 
bursting of the pod, however, a change occurs. The admission 
of air and sunlight causes a gradual unfolding of the hairy plexus, 
and the rapid consolidation of the liquid cell contents on the 
inner surface of the cell-wall gives them a greater thickness and 



COTTON. 



"3 



density, which is further increased by the gradual shrinking 
in of the walls themselves upon the cell contents. There is 
also a gradual rounding and thickening of the fibre, which in- 
creases by the deposition of matter on the inner wall of the cell. 
As this action is not perfectly uniform, arising from the unequal 
exposure of different parts of the fibres to light and air, it causes 
a twisting of the hairs, which is always a characteristic of cotton 
when viewed under the microscope, and the flat collapsed por- 
tions of the tube form so many reflecting surfaces, to which the 




Fig. 32. — Typical Cotton Fibres. 

A, broad, flat fibre near the base; B, thick rounded fibre; C, fibre near the 
pointed end; D, cut end of fibre. 

brightness of the fibre when stretched tight in the fingers is no 
doubt due. Another change also occurs at this stage, a change 
which corresponds to the ripening of fruit. In the earliest period 
of their formation the growing cells are filled with juices which 
are more or less astringent in character. Under the influence 
of light and air these cell contents undergo a chemical change, 
in which the astringent principles are replaced by more or less 
saccharine or neutral juices, until in the perfectly ripe cotton 
fibre the cell-walls are composed of almost pure cellulose. 

The cell-wall of the cotton is thin in comparison with that of 
the bast fibres, but in comparison with the other seed- hairs it 
is remarkably thick. This accounts for its much greater strength 



114 THE TEXTILE FIBRES. 

over the latter. In completely developed fibres, the thickness 
of the cell-wall is from one-third to two-thirds of the total thick- 
ness of the fibre itself. 

The quality of the cotton fibre depends not only on the species 
of the plant from which it is derived, but also on the manner 
of its cultivation. The conditions which exercise, perhaps, 
the greatest influence are : (a) the seed, {h) the soil, (c) the mode 
of cultivation, {d) the climatic conditions. The seed for sowing 
must be carefully and specially chosen for the purpose. A 
very dry soil produces harsh and brittle cotton, the fibres of 
which are very irregular in length; a moist and sandy soil pro- 
duces a very desirable cotton of long and fine staple. The best 
soil is considered to be a light loam, while a damp clay is regarded 
as the worst. Soils situated in proximity to the sea, and there- 
fore containing considerable saline matter, appear to furnish 
the most valuable varieties of cotton, and it is claimed that the 
sahne constituents of the soil have considerable influence on 
the growth and development of the cotton fibre. 

2. Varieties of Cotton. — ^The classification of the different 
species of cotton plant varies with different authorities; the most 
comprehensive, perhaps, is to classify the different varieties of 
the cotton plant as (i) the tree, (2) the shrub, and (3) the 
herbaceous species.* According to Parlatore all commercial 

* The following list of species of the cotton-plant are more or less recognized 
by botansists: 

G. album Hamilton, a synonym of G. herbaceum; commercially known as 
upland cotton; has a white seed. 

G. arboreum Linn., a tree-like plant; perennial; indigenous to India; pro- 
duces but little fibre. 

G. barbadense Linn., indigeneous to America and outlying islands; gives 
the highly prized sea-island cotton. 

G. brasiliense Macfad., a tropical species; belongs to the so-called "kidney- 
cottons"; the seeds adhere to one another in clusters. 

G. chinense Fisch. & Otto, a synonym for G. herbaceum; a Chinese cotton. 

G. croceum Hamilton, a synonym for G. herbaceum; possesses a yellow lint. 

G. eglandulosum Cav., a synonym for G. herbaceum. 

G. elatum Salisb., a synonym for G. herbaceum. 

G. fructescens Lasteyr., a synonym for G. barbadense. 

G. fuscum Roxb., a synonym for G. barbadense. 

G. glabrum Lam., a synonym for G. barbadense. 

G. glandulosum Stend., a synonym for G. herbaceum. 



COTTON. 115 

cotton is derived from seven species of the Gossypium, which he 
enumerates as follows: 

(i) G. barbadense, which comprises the long-stapled and 
silky-fibred cottons known as Barbadoes, Sea-island, Egyptian, 
and Peruvian. The plant reaches a height of from 6 to 8 ft., 

G. Jterbaceum Linn., usually considered of Asiatic origin; synonymous with 

G. hirsutum; ordinary upland cotton. 
G. hirsutum Linn., of American origin; Georgia upland cotton. 
G. indicum Lam., a synonym for G. herhaceum. 

G. jamaicense Macfad., a synonym for G. barbadense; grows in Jamaica. 
G. javanicum Blume, a synonym for G. barbadense; grows in Java. 
G. latifolium Murr., a synonym for G. herbaceum. 
G. leonimum Medic, a synonym for G. herbaceum. 
G. macedonicum Murr., a synonym for G. herbaceum. 
G. maritimum Tod., a synonym for G. barbadense. 
G. micranthum Cav., a synonym for G. herbaceum. 
G. molle Mauri, a synonym for G. herbaceum. 
G. nanking Meyen, a synonym for G. herbaceum. 
G. 7ieglectum Tod., indigenous to India; similar to G. arboreum; extensively 

grown in India; gives the Dacca and China cottons. 
G. nigrum Hamilton, a synonym for G. barbadense. 
G. obtusifolium Roxb., a synonym for G. herbaceum. 
G. oligospermum Macfad., a synonym for G. barbadense. 
G. paniculatum Blanco, a synonym for G. herbaceum. 
G. perenne Blanco, a synonym for G. barbadense. 
G. peruvianum Cav., a synonym for G. barbadense. 
G. punctatunt Schum. & Thonn., a synonym for G. barbadense. 
G. racemosum Poir, a synonym for G. barbadense. 
G. religiosum Par., a synonym for G. arboreum; so-called because its use is 

mostly restricted to making turbans for Indian priests; also because it 

grows in the gardens of the temples; it has the cultural name of Nurma 

or Deo cotton. Also a variety of G. barbadense. 
G. roxburghianum Tod., a variety of G. neglectuni; corresponds to the Dacca 

cotton of India. 
G. siamense Tenore, a synonym for G. herbaceum. 
G. sinense Fisch., a synonym for G. herbaceum. 
G. stocksii Masters, a synonym for G. herbaceum; claimed to be the original 

of all cultivated forms of this latter species. 
G. strictum Medic, a synonym for G. herbaceum. 
G. tomentosum, indigenous to the Sandwich Islands; the bark is used for 

making twine. 
G. tricuspidaium Lam., a synonym for G. herbaceum. 
G. vitifolium Lam., a synonym for G. barbadense. 
G. vitifolium Roxb., a synonym for G. herbaceum. 
G. wightianum Tod., a synonym for G. herbaceum; claimed by Todaro to be 

the primitive forms of the Indian cottons. 



Ii6 THE TEXTILE FIBRES. 

and has yellow blossoms. Owing to variations in the conditions 
of its cultivation, however, the present sea- island cotton has 
changed considerably from the original harhadense. This 
variety is employed for the spinning of fine yarns, such as are 
known in trade as "Bolton counts." 

(2) G. herbaceum, including most of the cotton from India, 
southern Asia, China, and Italy. It is an annual plant growing 
from 5 to 6 ft. in height ; unlike the harhadense variety, its seeds 
are generally covered with a soft undergrowth of fine down, 
which is an objectionable feature. The flower is yellow in color. 
This species is perhaps the hardiest of the cottons, and is cultivated 
over a wider range of latitude. It forms the source of nearly all 
the Indian cotton. It is used for the spinning of low- count 
yarns, also for the making of condenser yarns for the manufac- 
ture of flannelettes. 

(3) G. hirsutum, including most of the cotton from the 
southern United States, also known as upland cotton. The 
plant is shrubby in appearance, seldom reaching more than 
7 ft. in height; like the preceding variety, the seeds are also 
covered with a fine undergrowth of down. 

(4) G. arboreum, including the cotton from Ceylon, Arabia, 
etc. As the name indicates, it is a tree-like plant, and grows 
from 12 to 18 ft. in height. The fibres are of a greenish color 
and very coarse; its flowers are of a reddish color. 

(5) G. peruvianum, including the native Peruvian and Bra- 
ziUan cottons. This differs from other varieties of cotton in that 
it is a perennial plant ; the growth from the second and third years, 
however, only is utilized. 

(6) G. tahitense, found chiefly in Tahiti and other Pacific 
islands. 

(7) G. sandwichense, occurring principally in the Sandwich 
Islands. 

This classification is claimed to include all the commercial 
varieties of cotton; it is probable, however, that the last two can 
be included under the harhadense and hirsutum varieties, as 
they possess the same characteristics as these fibres. 

Other authorities on the botany of the cotton plant have rec- 



COTTON. 117 

ognized many more species than those above described. Agos- 
tino Todaro has described 52 varieties, while the Index Kewensis 
records 42 distinct species and refers to 88 others which it classi- 
fies as synonyms. Hamilton reduces the number of species to 
three, namely, the white-seeded, black-seeded, and yellow-hnted, 
assigning to these species the botanical names album, nigrum, 
and croceum. The chief difficulty experienced in the botanical 
classification of the cotton plant is the fact that it hybridizes very 
readily and has a tendency to suffer alteration in variety with 
change in the conditions of its cultivation or variation in the 
character of the soil or climate. 

Besides the varieties of cotton above enumerated, which are 
practically all which find any important commercial application, 
there is another plant which yields a fibre somewhat similar to 
cotton, and known as the silk-cotton plant. It belongs to the 
same natural order, Malvacea, as the ordinary cotton plant, but 
is of a different genus, being Salmalia instead of Gossypiuni. It 
grows principally on the African coast and in some parts of 
tropical Asia. The plant is rather a large tree, reaching from 
70 to 80 ft. in height. The blossoms are red in color, and the 
seeds are covered with long silky fibres, which are not adapted, 
however, for spinning. 

Although fibres from the different species of the cotton-plant 
all possess the same general physical appearance, nevertheless 
there are characteristic features in each worthy of careful obser- 
vation. 

Gossypium barbadense: Sea-island. — This constitutes the 
most valuable, perhaps, of all the different species. Its chief 
points of superiority are (a) its length, being more than half an 
inch longer than the average of other cottons; (b) its fineness of 
staple; (c) its strength; (d) its number of twists, which allow 
it to be spun to finer yarns; (e) its appearance, it being quite 
soft and silky. It is also characterized by a light-cream color. 
Sea-island cotton is mostly used for the production of fine yarns 
ranging from 120's to 300's; it is said that as fine as 2000's has 
been spun from it.* On account of its adaptability for merccr- 

* The "count" of cotton yarn means the number of hanks of 840 yards each 



Ii8 THE TEXTILE FIBRES. 

izing it is also largely employed for this purpose, in which case 
much coarser yarns are often prepared from it. Owing to the 
wide cultivation of sea- island cotton at the present time, for its 
growth is no longer strictly confined to the islands of the sea, it is 
difficult to make a definite statement as to its length of staple, as 
this will vary considerably with the method and place of cultiva- 
tion. The maximum length, however, may be taken as 2 ins., and 
the minimum as if ins., with a mean of if ins. Florida sea-island 
cotton is very similar in general characteristics to sea -island 
proper, possessing about the same mean length of staple, but being 
somewhat less in the maximum length. Both of these varieties 
of sea-island show a maximum diameter of 0.000714 in., a 
minimum of 0.000625 in., and a mean of 0.000635 in. Fiji 
sea-island is less regular in its properties than the two preceding 
varieties, and though its maximum length is somewhat greater 
than sea-island itself, yet the mean length is about the same, as 
is also the diameter. This cotton, however, has a very irregular 
staple and contains a large percentage of imperfect fibres, which 
causes the waste to be rather high. The number of twists in the 
fibre is also less and does not occur as regularly. Gallini Egyptian 
cotton is sea-island cotton grown in Egypt. It is somewhat 
inferior to the American varieties in general properties. It pos- 
sesses a yellowish color which distinguishes it from the product 
of all other countries. The maximum length of the fibre is if 
ins., the minimum i\ ins., and the mean i| ins. The fibres differ 
very little in their diameter, the average being 0.000675 i^i- 
Peruvian sea-island is somewhat coarser in structure than the 
sea-island proper, being more hairy in appearance; it has a 

contained in i lb. The size 120's, for instance, means cotton yarn of such 
fineness that 120 hanks of 840 yards (=100,800 yards) weigh i lb. The French^ 
method of numbering is based on the decimal system, and the count means 
the number of hanks each 1000 meters in length required to weigh 500 grams. In 
order to change from French to Enghsh count, multiply the former by 0.847, 
or H- The Belgian method of counting is to use the number of 840-yard hanks 
in 500 grams. The Austrian system is the number of hanks of 950 ells each con- 
tained in 500 grams. The English system is the one mostly used, being employed 
in England, America, India, Germany, Italy, and Switzerland, and even in parts 
of Austria. 



COTTON. 119 

slight golden tint. In staple it varies from i| ins. in length to 
if ins., with a mean of i^ ins. Tahiti sea-island resembles the 
Fiji variety very closely; it has a creamy color. The length of 
staple varies from if to i J ins., with a mean of i^^ ins. It shows a 
considerable percentage of imperfect fibres due to a short under- 
growth on the seed. Its average diameter is 0.000641 in. 

Gossypium herbaceum. — Smyrna cotton is grown principally 
in Asiatic Turkey. It has a rather characteristic appearance 
under the microscope, being very even in its diameter but irregu- 
lar in its twist, showing many fibres where the twist is almost 
entirely absent. In length the staple varies from i^ to I ins., 
with a mean of i in.; the mean diameter is about 0.00077 in. 
Brown Egyptian cotton is supposed to be indigenous to that 
country. It is characterized by a fine golden color, and great 
toughness and tensile strength. It is, however, shorter and 
coarser than the Galhni cotton. In length of staple it varies 
from i^ to i|- ins., with a mean of 1.31 ins.; the mean diameter 
is 0.000738 in. African cottons are all derived from the her- 
baceum species. These cottons have a slight brownish tint, 
and always contain a large amount of short fibre. The fibres 
also vary much in diameter and thickness of the tube-walls, and 
many exhibit a transparent appearance under the microscope. 
Yarns made from these cottons are always uneven on the surface. 
The length of staple varies from 1-1% to | ins., with an average of 
1.03 ins.; the mean diameter is 0.00082 in. Hingunghat cottons 
are Indian varieties; the quality of these varies with the soil and 
climate of the province in which they are grown. As a rule, 
they are of rather inferior grade; the best variety is the Surat 
cotton. Under the microscope the Hingunghat cotton shows 
much variation in diameter, although it possesses fewer twists 
than the better grades of cotton, yet, unlike the African varieties, 
it shows very few fibres without any convolutions at all. In 
length of staple it varies from i^V to | ins., with a mean of i .03 ins. ; 
the average diameter is 0.00084 in. Broach, Tinnevelly, Dharwar, 
Oomrawuttee, Dhollerah, Western Madras, Comptah, Bengal, and 
Scinde are other varieties of Indian cotton, all belonging to the 
herbaceum species. They have the same general properties and 



I20 THE TEXTILE FIBRES. 

staple as the preceding, becoming more and more inferior, how- 
ever, in the order of the Hst given. 

Gossypium hirsutuni. — White Egyptian, unHke the brown 
variety described above, is not indigenous, but was transplanted 
from America. In length of staple it varies from i| to i^ ins., 
with a mean of i^- ins.; the diameter averages 0.00077 i^^- This 
cotton shows a large number of fibres having but a partially 
developed spiral form. Orleans cotton is the typical American 
variety, and is perhaps the best of the American cottons. The 
fibres are quite uniform in length, having an average staple of 
about I in. and a mean diameter of 0.00076 in. It is almost 
pure white in color. Texas cotton much resembles the fore- 
going, but has a slight golden color; its length and diameter of 
staple are the same. Upland cotton is another very similar variety; 
its length of staple, however, is somewhat less than the foregoing, 
averaging but it in. Its twist is rather inferior to the Orleans, 
and it shows a larger number of straight fibres. Mobile cotton 
is the most inferior of the American varieties; it varies in length 
of staple from i to | in., with a mean of | in. ; its average diameter 
is 0.00076 in. It shows about the same microscopic appearance 
as upland cotton. Santos cotton comes from Brazil; it is not 
much in demand on account of its inferior quahty. 

Gossypium peruvianum. — Rough Peruvian; this cotton has a 
light creamy color and is rather harsh and hairy in feel. In 
length of staple it varies from ijV to i|- ins., with a mean of 1.28 ins. ; 
its mean diameter is about 0.00078 in. Most of the fibres are 
only partially twisted. Smooth Peruvian has a soft, smooth feel, 
but the staple is not so strong as the preceding. The length is 
about the same as the foregoing, as is also the diameter. Per- 
nambuco has a slight golden color and feels harsh and wiry. It 
is a variety of Brazilian cotton. It is rather regular in length 
of staple, the mean being i^ ins. The diameter averages 0.00079 
in. Under the microscope the twists appear regular and well- 
defined. Maranhams cotton is very similar to the preceding in 
microscopic appearance and length and diameter of staple. 
Ceara is a Brazilian cotton, rather inferior to the others by reason 
.of its considerable variation in length of staple. Maceio is a 



COTTON. 121 

similar variety, but somewhat harsher. West Indian cottons 
nearly all belong to the peruvianum species; they are usually 
long in staple and harsh and wiry in feel, and only of moderate 
strength. The length is quite uniform and averages i\ ins. 
The diameter varies considerably, but has an average of about 
0.00077 ^^- The twist is short and very uniform, surpassing 
even sea-island in this respect. 

Chinese cotton, also known as Nankin cotton, is classified 
as G. religiosum; it yields a naturally colored fibre, being rather 
dark yellowish brown. It grows principally in China and Siam. 

3. Vegetable Silks. — Besides the cotton derived from the 
Gossypium family, there is a similar seed-hair fibre obtained 
from what is known as the cotton-tree or Bombax cotton, or vege- 
table down, the growth of which is confined almost exclusively 
to tropical countries.* The fibre is soft, but rather weak as 
compared with ordinary cotton; in color it varies from white 
to yellowish brown, and it is quite lustrous. Physically Bombax 
cotton differs from true cotton in not possessing any spiral twist 
and showing irregular thickenings of the cell- wall. In its chemical 
constitution it differs from the other cotton by containing a 
certain amount of lignified tissue ; consequently it gives a yellow 
coloration when treated with anilin sulphate or iodin and sul- 
phuric acid, and by these tests may be distinguished from true 
cotton, t 

* There are a number of varieties of vegetable down, of which the following 
are the principal: 

Bombax ceiba, from tropical America. 

Bombax heptaphyllum, from same countries. 

Bo?nbax malabaricum, from south Asia and Africa. 

Gossypium cochlospernum, from India. 

Ochroma lagopus, from the West Indies. 

Chorisia speciosa, from South America. 

Eriodendron anjractuosum, or Bombax pentandrum, from south Asia. 
The Rama limpa cotton of Brazil is obtained from Bombax heptophyllum. 
The product known in Holland as kapok is obtained from B. pentandrum. I'he 
Edredon vegetal and Pattes de lievre of the French trade are products of Ochroma 
lagopus. The Ouate v/g(/tal is a mixture of Bombax, Ochroma, and Chorisia 
varieties. 

f The microscopic characteristics of vegetable down are as follows: The 
fibre consists of a single hair possessing a conical shape; the base is frequently 



122 THE TEXTILE FIBRES, 

Another seed-hair which is utihzed as a fibre is Asclepias 
cotton, which is also known as vegetable silk, as the fibres possess 
a very high lustre. This cotton, however; is quite brittle in nature 
and possesses but little strength; hence attempts at spinning it 
have not proved very successful. As this fibre is also somewhat 
lignified, it may be distinguished from true cotton by the appH- 
cation of the above-mentioned tests. When examined under 
the microscope it shows thickened streaks in the cell-wall which 
serve to distinguish it from Bombax cotton.* 

swollen or lace-like in structure. The length varies from i to 3 cm. The cross- 
section is circular, so that the fibres are not flat as with cotton. The contents 
of the inner canal consist of air and a dried-up protoplasmic membrane. As 
all vegetable downs are more or less lignified, their fibres swell but shghtly when 
treated with Schweitzer's reagent. The thickness of the fibres varies from 20 
to 50 fx. 

Hohnel gives the following description of the chief varieties of vegetable down: 

1. Bombax ceiba; length i to 1.5 cm. B. malabaricum has a fibre-length of i 
to 2 cm., and B. heptaphyllum from 2 to 3 cm. The last is by far the longest 
and strongest variety, and is sometimes used in spinning. The diameter of the 
Bombax fibres varies from 19 to 43 jx, with an average of 25 ^. 

2. The hairs of Eriodendron anjractuosum are very similar to the preceding, 
and it is difficult to distinguish between them. 

3. The fibres of Ochroma lagopus are 0.5 to 1.5 cm. in length, and are thicker 
at the middle than at the ends. The cell-wall is quite thick, and the fibres are 
more highly lignified than the foregoing. 

Pulu fibre can also be classed under the general name of vegetable down. 
It is the hair obtained from the stems of fern-trees, more especially the Cibotium 
glaucum (from Sandwich Islands). The fibres are lustrous, of a golden-brown 
color, very soft and not very strong. They are about 5 cm. in length, and are 
composed of a series of very flat cells pressed together in a ribbon-like form. The 
fibre is only employed as a stuffing material and is never woven. 

* There are several varieties of vegetable silks, chief among which are the 
following: Asclepias curassavica, from the West Indies; Calotropis gigantea, 
from south Asia and Africa; Marsdenia, from India; Beaumontia grandifioria, 
from India; Strophantus, from Senegal. True vegetable silks as a rule may be 
recognized as follows: They are 4 to 6 cm. in length; possess a silky lustre; in 
color are white to yellow or reddish yellow; and are stiff. Their thickness is 
sometimes as much as 80 fi, but more generally 35 to 60 ^. The fibre is rela- 
tively thin-walled, but shows frequently on the inside several thickened longi- 
tudinal ridges, which are sometimes very apparent and at others scarcely notice- 
able. The ridges are semicircular in cross-section, though sometimes flat and 
broad. The ridges give the cell-wall the appearance of being uneven in thick- 
ness. The ridges form the chief microscopical feature of vegetable silk, and 
serve to distinguish these fibres from vegetable downs, which are otherwise very 
similar. The cross-section of the fibre is circular, and the cell-wall is lignified. 



COTTON. 123 

Cotton-silk is a seed-fibre which appears to be more or less 
identical with the foregoing. It is derived from an Indian plant 
botanically classified as Salmalia, a genus of Malvacece; the 
plant is a rather large tree, attaining the height of 70 to 80 ft. 
Although the fibre is very beautiful in appearance, having the 
texture and lustre of silk, it is not suitable for purposes of spinning, 
as its tensile strength is quite low. Under the microscope the 
j&bres appear as thin, smooth, transparent tubes without the 
longitudinal markings of the silk fibre, and differing from cotton 
in not showing the twists and irregularities of that fibre, and 
in not being flattened but cylindrical in appearance. Cotton- 
silk may be readily distinguished ' from silk by igniting a fibre 
in a flame, when the former will burn with great rapidity, whereas 
silk will fuse and give off the characteristic odor of a burning 
animal fibre. Cotton-silk is evidently a form of cellulose fibre; 
its silky appearance being due to the delicacy and thinness of 
the cell-walls and their smooth surface. It is very sensitive to 
the action of dilute acids; towards dyestuffs it behaves like 
cotton, not combining with the basic colors except after a pre- 
vious mordanting. There are several other plants which yield 
seed- hairs, which, as a rule, are not of much value for purposes 
of spinning and weaving; but they find rather extensive use 
for upholstery purposes and twines. As a rule, these fibres are 
colored red by phloroglucol and hydrochloric acid, and yellow 
with anihne sulphate, showing the presence of lignified tissue. 
Usually the fibres are somewhat yellow in color and possess 
considerable lustre. 



CHAPTER X. 

THE PHYSICAL STRUCTURE AND PROPERTIES OF COTTON. 

I. Physical Structure. — Physically the individual cotton fibre 
consists of a single long cell, with one end attached directly to the 
surface of the seed. While growing, the fibre is round and cylin- 
drical, having a central canal running through it; but after the 
enclosing pod has burst, the cells collapse and form a fiat ribbon- 
like fibre, which shows somewhat thickened edges under the 
microscope. The juices in the inner tube, on the ripening of the 
fibre, are drawn back into the plant, or dry up, and in doing so 
cause the fibre to become twisted into the form of an irregular 
spiral or screw-like band.* Fibres that have not ripened differ 
somewhat in these characteristics, being straight and having the 
inner canal stopped up, in consequence of which they do not spin 
well and are difficult to dye, showing up as white specks in the 
finished goods; this is known as dead cotton. The presence of an 
inner canal in the cotton fibre no doubt adds to its absorptive 
power for liquids, and its capillary action allows cotton to retain 
salts, dyestuffs, etc., with considerable power; but too much im- 
portance in this respect must not be attributed to the canal, for 
when cotton is mercerized the canal is almost entirely obliterated 
by the walls being squeezed together, and yet mercerized cotton 
is much more absorptive of dyes, etc., than ordinary cotton. 
The capillarity of the cotton fibre is no doubt principally due to 
the existence of minute pores which run from the surface inward. 
The crystallization of salts in these pores and in the central canal 
may lead to the rupturing of the fibre, as, for instance, when 
filter-paper is made by disintegrating cotton fibres by saturating 
them with water and then freezing them. 

The cotton fibre is rather even in its diameter for the greater 

* The number of twists in the cotton fibre in the raw state is said to be from 
300 to 500 per inch. 

124 



THE PHYSICAL STRUCTURE AND PROPERTIES OF COTTON. 1^5 



part of its length, though it gradually tapers to a point at its out- 
growing end. The different varieties of cotton show consider- 
able variation, both in length and diameter of fibre; in sea-island 
cotton the length is nearly 2 ins,, while in Indian varieties it is 
often less than i in. The diameter varies from 0.00046 to o.ooi 
in. ; the longest fibres having the least diameter. 

The following table of the length and diameter of different 
varieties of cotton fibres has been collated as a mean of several 
observers : 



Name of Cotton. 


Length 
in mm. 


Diameter 
in fu 


Name of Cotton, 


Length 
in mm. 


Diameter 
in ft. 


Sea-island 


41.9 
46.6 
39-0 
39-3 
45-7 
48.7 
42.9 
38.9 
32.1 

37-2 
34-4 
31.8 

28.5 


965 

"16.18' 
16.7 
16.3 
15-3 
16.7 
17. 1 
18.7 

19-5 
22.8 
18.8 
20.4 
20.0 

20.0 

21-5 

21.5 


West Indian 

1 American 


32.3 


19.6 
20.9 
19.2 
19.4 
16 6 


Edisto 


Wodomalam 


Orleans 


27.0 
29-5 
24-3 

25.0 

25-4 
24.2 
25.0 
25.1 
27.6 


John Isle 

Florida 


Upland 


Te.xas 


Fitschi 


Mobile 


19.4 

10.3 

3-4 


Tahiti 


Georgia 


Peruvian 

EevMian 


Mississippi 

Louisiana 

Tennessee 

African 


Gallini 


IS.O 

^0 8 


Brown 


White 


Indian 


19-3 


Smyrna 


1 Hingunghat 

Dhollerah 

Broach 


28.3 
28.2 
20.9 
23.0 
23.6 
24.1 
23.8 
21.8 
20.4 

25-7 
21.4 


Brazilian 




Maranham 


28.8 
35-2 
30.2 
29.7 
28.1 

29-3 
29.9 
30.0 
37-5 


''I 8 


Pernambuco 

Surinam 


Tinnevelly 

Oharwar 

Oomrawuttee. . . . 

1 Comptah 

Madras 


21 .0 


Paraiba 




Ceara 




Maceo 


->! 8 


Peruvian rough 

Smooth 


Scinde 




Bengal 


23-7 
24.1 


Agerian 


Chinese 







Evan Leigh {Science of Modcrri Cotton Spinning) gives the 
following summar}- of the length and diameter of cotton fibres: 





Kind of Cotton. 


Length in Ins. 


Diameter in Ins. 




Min. 


Max. Mean. 


Min. 


Max. 


Mean. 


United States . . 
Sea-islands .... 
South America. 
EffVDt 


New Orleans. . . 
Long stapled. . . 

BraziHan 

Egyptian 

Native 

American seed . . 
Sea-island seed . 


0.88 
1. 41 
1. 03 
1.30 
0.77 

a. 95 
1.36 


1. 16 
1.80 
I-3I 
1-52 
1.02 
1 . 21 
1.65 


1 .02 
I. 61 
1. 17 
1. 41 
0.89 
1.08 
1.50 


.000580 
. 000460 
. 000620 
. 000590 
. 000649 
.000654 
.000596 


.000970 
.000820 
. 000960 


.000775 
. 000640 
. 000790 
. 000655 
. 000844 
.000825 
.000730 


India -j 


. 000040 
. 000996 
.000864 



126 



THE TEXTiIe fibres. 



Hannan gives the following varieties and qualities of cotton 
to be met with in commerce: 



Types. 


Variety. 




0) 


Counts. 


Use. 


Properties. 


Sea-island . . 


Edisto 


2. 20 


. 00063 


300-400 


Warp 
or weft 


Long, fine silky, 
and of uniform 
diameter 




Florida 


1.85 


. 00063 


150-300 


do. 


Shorter, but similar 
to above 




Fiji 


1-75 


. 00063 


100-250 


do. 


Less uniform in 
length, but silky 
and cohesive 




Tahiti 


1.80 


. 00063 


" 


do. 


Gcod, fine, and 
glossy staple 


Egyptian. . . 


Brown 


1.50 


. 00070 


120-down 


do. 


Long, strong, high- 
ly endochromatic 




Gallini 


1.60 


. 00066 


250-down 


Warp 


High class staple of 
good strength 




Menouffieh. .. 


1.50 


u 


200-down 


Weft 


Of good staple and 
lustre 




Mitafiffi 


1.25 


(( 


100 


Warp 
or weft 


Fairly good staple 




White 


1. 00 


. 00078 


70 


do. 


Pearly white, good 
long staple 


Peruvian. . . 


Rough 


1.25 


.00078 


50-70 


Warp 


Strong, wooly, and 
harsh staple 




Smooth 


1. 00 


" 


(( 


Weft 


Less wooly, and 
softer staple 




Red 


1.25 


(( 


40-50 


Warp 


Color weaker and 








harsher than 














brown Egyptian 


Brazilian. , . 


Pernams 


1.50 


.00079 


■ 50-70 


Warp 


Strong and wiry 




Maranhams, . 


1-15 


" 


50-60 


do. 


Harsh and wiry 




Ceara 


I-I5 




60 


Weft 


Good, white, and 
cohesive staple 




Paraiba 


1.20 


(( 


50-60 


Warp 
or weft 


Fairly strong, harsh, 
of good color 




Rio Grande. . 


i-iS 




40-50 


Weft 


Soft, white, and 
harsh staple 




Maceio 


1.20 


. 00084 


40-60 


Warp 
or weft 


Soft, phable, and 
good for hosiery 




Santos. . .. . . 


1.30 




50-60 


Weft 


Exotic from Ameri- 
can seed, white 
and silky staple 




Bahia 






40-50 


Warp 
or weft 


Fairly strong, but 
harsh and wiry 


- 








American. . . 


Orleans 


I.I 


.00077 


34-46 


Warp 
or weft 


Medium length, 
pearly, white 




Texas 


1.05 




32-40 


do. 


Similar to above, 
rather harsher and 
more glossy 




AUanseed. . . . 


1.20 




50-60 


Warp 


Good, white, long; 
blends with brown 
Egyptian 



THE PHYSICAL STRUCTURE AND PROPERTIES OF COTTON. 127 



Types. 


Variety. 




i 
5 


Counts. 


Use. 


Properties. 


American. . . 


Mobile 


1 .00 


. 00076 


40-50 


Warp 
or weft 


Even-running sta- 
ple, soft and cohe- 
sive 




Norfolks 


I. GO 


i( 


40-50 


Weft 


Used for Oldham 
counts of 5g's 




St. Louis 


0.90 




30-32 


Warp 


Staple irregular, 
glossy, but short 




Ronoaks 


0.90 


<< 


30-34 


do. 


A white and strong 
staple 




Boweds 






36 
60 


Weft 


Similar to uplands 
Strong, creamy or 




Benders 


I. 10 


.00077 


Warp 














white, for Turkey- 














red dyes 




Memphis. . . . 


I. GO 




40-50 


do. 


Bluish white, for ex- 
tra hard twists 




Peelers 


1.25 




60-80 


Weft 


Long, silky, fine sta- 
ple; adapted foi 
velvets, etc. 




Uplands 


I. 00 




36-40 


do. 


Glossy when clean,, 
apt to be dull, 
sandy, and leafy 




Alabama 


G.90 




26-30 


Warp 
or weft 


Short staple, of less 
strength, varying 
color 




Linters 






8-10 


Weft 


Short stapled gin 
waste 
















Tennessee. . . . 


0.90 




28 


Warp 
or weft 


Of varying length 
and color 


Creek 


Smyrna 


1.25 




36-40 


Warp 


Harsh and strong, 
adapted for double 
yarns. 


African. . . . 


Lagos 


0.80 




20-26 


Weft 


Dull and oil-stained; 
irregular in length 
and strength 


West Indian 


Carthagena. . 


I.SG 




26 


Warp 


From exotic seeds; 
fairly strong 




La Guayran . 


1.20 





40 


Warp 
or weft 


Irregular and short, 
but silky staple 


China 


China 


I.OG 




30 


Weft 


Harsh, short, and 
white 


Australian . 


Queensland. . 


I-7S 


. 00066 


I20-20G 


Warp 
or weft 


Long, white, silky, 
fine diameter 


East Indian 


Oomrawuttee 


I. GO 


. 00083 


26-32 


Warp 


Short, strong, and 
white 




Hingunghat. . 


I.GG 


(( 


28-36 


Weft 


Best white Indian 
staple 




Comptah. , . . 


1.05 






Warp 


Generally dull, and 
charged mth leaf 










or weft 




Broach 


O.9G 




28-36 


Weft 


Like Hingunghat, 
gives good white 
weft 




Dharwar 


I .00 




28 


Warp 


Exotic from Ameri- 
can seeds 



I2S 



THE TEXTILE FIBRES. 



Types. 


Variety. 




u 

<u 

s 


Counts. 


Use. 


Properties. 


East Indian. 


Assam 


0.50 




15-20 


Warp 


White, but harsh. 
To blend with 
other cottons 




Bengals 


0.80 




20-30 


Warp 
or weft 


Dull and generally 
charged with leaf 




Bilatee 


0.50 




10-20 


do. 


Weak, brittle, and 
coarse 




Dhollerah 


0.70 




15-20 


do. 


Strong, dull, and co- 
hesive 




Surat 


0.60 




10-15 


do. 


Dull and leafy, often 
stained 




Scinde 


0.50 




to 10 


do. 


Very strong, dull, 
short, and poor 
staple 




Tinnevelly. . . 


0.80 




24-30 


do. 


Lustrous white, soft, 
and adapted for 
hosiery 




Bhownuggar 


1 .00 




28-30 


Warp 


White when clean; 
often leafy and 
dirty 




Cocoanada. . . 


0.70 




10-14 


Brown 
weft 


Brown and dull; 
used as quasi- 
Egyptian 




Bourbon 


1. 00 




30 


Weft 


Exotic; of good sta- 
ple; scarce 




Khandeish. . . 


0.80 


. 00083 


20-26 


Warp 
or weft 


Similar in class to- 
Bengal 




Madras , o r 


0.70 




15-20 


do. 


Used for low yarns 




Westerns 










in coarse towelling, 
etc. 




Rangoon 


0.60 




to 10 


Warp 
or weft 


Weak, dull, oftea 
stained and leafy 




Kurrachee. . . 


0.90 




28 


do. 


Fairly strong, dull,, 
and leafv 


Italian 


Calabria 


0.90 




26-28 


do. 


Fairly strong, irreg- 
ular and dull, leafy 


Turkey 


Levant 


1. 25 


.00077 


36-40 


Warp 


Harsh, strong, and 
white 



Hohnel gives the following table for the thickness of different 
varieties of cotton : 

mm. 
North American: 1000 

Sea-island 14 

Louisiana and Alabama 17 

Florida 18 

Upland and Tennessee ■ 19 

Southern and Central American I5~2r 

Average 19 



THE PHYSICAL STRUCTURE AND PROPERTIES OF COTTON. 129 

mm. 

East Indian: 1000 

Dollerah and Bengal 20 

Madras 28 

Chinese: 

Nankin 25-40 

Egyptian: 

Macco 15 

Levianthan 24 

European: 

Spanish 17 

Italian 19 

According to Wiesner the thickest part of the cotton fibre is 
not directly at the base, but more or less towards the middle. 
He gives the following measurements of thickness at different 
parts of the fibre: 



Position. 


G. arboreum, 
2 5 mm. long. 


G. acuminatum, 
28 mm. long. 


G. herbaceum, 
2$ mm. long. 




mm. 
1000 


mm. 
1000 


mm. 
1000 


Point 











I 
2 


8.4 
21 


4.2 
21 .6 


4.2 
5-8 


3 
4 
5 
6 


29 

25 
29 

25 


16.8 
29.4 
17.0 

21. I 


lO.O 

16.8 
21.0 
16.9 


7 
Base 


21 

17 


21. I 
21.0 


21.0 
16.8 


Mean 


19-5 


16.9 


12.5 



The length of the cotton fibres attached to a single seed is by 
no means constant. The longest fibres usually appear at the 
crown of the seed, while the shortest occur at the base. There 
is also frequently an undergrowth of very short fuzzy fibres. In 
ginning, the very short fibres are ordinarily not removed from 
the seed, but always more or less do come in with the ginned 
cotton. These short fibres are termed "neps," and their pres- 
ence in any considerable amount materially affects the commercial 
value of the cotton. This short undergrowth of neps appears to 
be made up of incompletely developed or immature fibres, though 
neps may also arise through excessive breaking of fibres by im- 
perfect manipulation in the carding and spinning processes. 



13° 



THE TEXTILE FIBRES. 



Bowman {Structure of the Cotton Fibre) gives the following 
table showing the extreme variation in the length and diameter 
of different kinds of cotton : 



Cotton. 


Variation in 
Length. 


Variation in 
Diameter. 


American (Orleans) 


o. 28 in. 

0-39 " 
0.28 " 
0.22 " 
0.25 " 


0.000390 in. 
0.000360 " 
0.000340 " 
0.000130 " 
0.000391 " 











Bowman calls attention to the fact that Egyptian cotton is the 
most regular in both length and diameter; while sea- island cot- 
ton, though possessing the greatest length and fineness of staple, 
also exhibits the greatest variation. It is also noticeable that the 
variation in the diameter i's proportionately very much larger 
than the variation in the length. Bowman also gives an inter- 
esting comparison of the size of the individual cotton fibre with 
objects of common experience. If a single fibre of American 
cotton were magnified until it becomes i in. in diameter, it would 
be a little over 100 ft. long, while a sea-island fibre of the same 
diameter would be about 130 ft. It requires from 14,000 to 
20,000 individual fibres of American cotton to weigh i grain, hence 
there are about 140,000,000 in each pound, and each fibre weighs 
on an average only about 0.00006 gr. If the separate fibres con- 
tained in one pound were placed end to end in a straight fine, 
they would reach 2200 miles. 

Hohnel gives the following table of the different varieties of 
cotton arranged according to their length of staple : 



Gossypium harhadense 



vitijolium 

conglomeratum 

acuminatum 

arboreum 

herbaceum 



(Sea-island) 4 . 05 cm. 

(Brazilian) 4.00 " 

(Egyptian) 3.89 " 

(Pernambuco) 3-59 " 

(Martinique) 3.51 " 

(Indian) 2 . 84 " 

(Indian) 2.50 " 

(Macedonian) i .82 " 

(Bengal) 1.03 " 



THE PHYSICAL STRUCTURE /fND PROPERTIES OF COTTON. 131 

From its behavior with a solution of ammonio-copper oxide, 
the cotton fibre appears to consist of four distinct parts struc- 
turally. When treated with this solution and examined under 
the microscope, the fibre is seen to swell, but not uniformly; it 
seems that at regular intervals there are annular sections which 
do not swell.* The result is that the fibre assumes the form of a 
distended tube tied at intervals somewhat after the manner of a 
string of sausages. Soon the main portion of the fibre begins to 
dissolve, whereupon the walls of the central canal are seen quite 
prominently; the dissolving action proceeds rapidly, but appar- 
ently there is a thin cuticular tissue surrounding the fibre which 
resists the action of the solvent for a much longer time than the 
inner portion. The walls of the central canal also resist the 
action of the liquid to even a greater extent than the external 
tissue; the annular contracted ligatures in the fibre also persist 
after the rest of the fibre has dissolved. Thus we have four 
structural parts made evident (see Fig. 37) : 

(a) The main cell-wall, probably composed of pure cellulose, 
and rapidly and completely soluble in the reagent. 

ib) An external cuticular fibre, probably of modified cellulose, 
and more resistant to the action of the reagent. 

(c) The wall of the central canal, which resists the solvent 
power of the reagent even more than the cuticle. 

{d) The annular ligatures surrounding the fibre at intervals, 
which persist even after the canal- walls have dissolved. 

O'Neill, (in 1863) first pointed out this complex structure of 
the cotton fibre. He says: "I beheved that in cotton-hairs I 
could discern four different parts. First, the outside membrane, 

* Hohnel considers these ligatures as merely parts of the cuticle ; he explains 
their formation by the fibre swelling so considerably as to rupture the undisturbed 
cuticle, which in places adheres to the fibre in the form of irregular shreds which 
are visible only with difficulty. In other places where the rupture occurs obliquely 
to the length of the fibre, the cuticle becomes drawn together in annular bands 
surrounding the fibre, while between these rings the much-distended cellulose 
protrudes in the form of globules. The inner membrane or canal which persists 
after the rest of the fibre has dissolved is an exceedingly thin tissue of dried proto- 
plasm which was contained in the living fibre. On bleached cotton the cuticle 
may be almost entirely lacking, and hence such fibres will not exhibit the charac- 
teristic appearance above mentioned. 



132 THE TEXTlLt FIBRES. 

which did not dissolve in the copper solution. Second, the real 
cellulose beneath, which dissolved, first swelling out enormously 
and dilating the outside membrane. Thirdly, spiral fibres, 
apparently situated in or close to the outside membrane, not 
readily soluble in the copper liquid. These were not so elastic 
as the outside membrane and acted as strictures upon it, pro- 
ducing bead-like swellings of a most interesting appearance; and 
fourthly, an insoluble matter, occupying the core of the cotton- 
hair, and which resembled very much the shrivelled integument in 
the interior of quills prepared for making pens." He also notes 
that the insoluble outside membrane was not evident on bleached 
cotton, hence concluding that either it had been dissolved away, 
or some protecting resmous varnish had been removed, and 
then it became soluble. He also obtained the same general 
results by treatment with sulphuric acid and chloride of zinc in 
place of the ammonio-copper solution. 

According to Butterworth, who observed the cotton fibre 
treated with the ammonio-copper solution under a magnification 
of 1600 diameters, there are spiral threads apparently crossing 
and tightly bound round the fibre at irregular distances, also 
spiral threads passing from one stricture to another; the core of 
the fibre has a spiral form, and in cross-section shows the presence 
of concentric rings (see Figs. 35 and 36). 

There appears to be some difference in the action of ammonio- 
copper solution on fibres of different physiological structure. 
Immature or unripe fibres dissolve readily without exhibiting 
any structural differences. The tubular-shaped fibres swell out 
as a whole and finally dissolve without showing any structural 
modifications, except that in many cases an inner core is left. 

Examination with the highest microscopic powers has not 
shown any cellular structure pertaining to the cellulosic contents 
of the cotton fibre ; it is probably composed of fine layers super- 
imposed one upon the other. 

2. Microscopical Properties. — ^The microscopical characteris- 
tics of the cotton fibre are so pronounced as to readily differentiate 
it from all others. As already noted, it presents the appearance 
of a flat, ribbon-like band more or less twisted on its longitudinal 



THE PHYSICAL STRUCTURE AND PROPERTIES OF COTTON. 133 

axis (see Fig. ^3). The cell- wall is rather thin and the lumen 
occupies about two-thirds of the entire breadth and shows up 




Fig. ^;^. — Unripe Cotton Fibres (X350). 
Showing a flat, ribbon-like form and thin and almost transparent appearance. 

ver}' prominently in polarized Hght. Between its thickened 
edges the fibre exhibits the appearance of a finely granulated 
surface. Fibres of dead cotton, or those which have not reached 
their full maturity, are seldom twisted spirally and do not have 
a lumen, but are thin, transparent bands (see Fig. 34). 

. Microscopically cotton fibres differ considerably among them- 
selves, but in general may be divided into four classes : 

(a) Fibres exhibiting a smooth, straight, flat appearance 
with no suggestion of internal structure. This includes immature 
cotton fibres and also fibres which have overripened by not 
being picked until some time after attaining full maturity. The 
external wall of the fibre is very thin. 

(b) Fibres exhibiting a normal appearance through some 
portions of their length, and in other parts a structureless 
appearance as in (a). This may be termed "kempy" fibre; the 
solid, tubular portion of the fibre is particularly resistant to 
the absorption of liquids and dyestuffs, and consequently remains 
uncolored while the rest of the fibre is dyed. 

(c) Straight, tubular fibres exhibiting a well-defined internal 
structure and a transparent cell-wall of var}'ing thickness. 



134 



THE TEXTILE FIBRES. 



(d) Normal structure of twisted, band-like form. 

In cross- section the immature fibres show only a single line 
with no structure, and but little or no indication of an internal 
opening. The mature fibre is thicker in cross- section and exhibits 
a central opening. 

The most characteristic of the microchemical reactions 
for cotton is that with ammoniacal copper solution, already- 
described. With bleached cotton the external cuticle may be 
absent, and hence such a fibre may not show any distension. 




Fig. 34. — Root of Cotton Fibre (X350). 
Showing the iiregular fracture caused by the fibre being torn from the seed; at 
the broad, flat portion of the base of the fibre may also be seen the longitudinal 
wrinkles and the cross-fractures of the cuticle. 



With iodin and sulphuric acid the cotton fibre becomes blue 
in color, though the cuticle remains colorless. Tincture of 
madder gives an orange color; fuchsin produces a red color 
which is destroyed by the addition of ammonia. Flax does 
not show this latter reaction, hence this serves as a chemical means 
of distinguishing between cotton and linen. Anhydrous stannic 
chloride gives a black color, and sulphuric acid dissolves the 
cotton fibre rapidly. 

3. Physical Properties. — The natural, spiral-like twist present 
in the cotton fibre causes the latter to be especially adaptable to 
purposes of spinning. The spinning qualities of the cotton 



THE PHYSICAL STRUCTURE AND PROPERTIES OF COTTON. 135 

fibre, however, depend not only on the nature and amount of 
twist which causes the individual fibres to lock themselves firmly 




Fig. 35.— Cotton Fibre, Swollen with Schweitzer's Reagent (X500). 
Showing the walls of the internal canal, and the spirally fibrous structure of the 

cellulose wall. 

together, but also on the length and fineness of staple. These 
three qualities in general will designate the character and fineness 




Fig. 36. — Portion of Fig. 35 very highly magnified (X2000). 
The structure of the cellulose is here plainly apparent. 



of yarn which may be spun from any sample of cotton, 
island cotton lends itself to the spinning of very fine yarnSj 



Sea- 



136 



THE TEXTILE FIBRES. 



spun to even 300 's (that is, 300 hanks of 840 yds. each would 
weigh I lb.), and in an experimental manner this cotton has 
even been spun as fine as 2000 's. 

In its tensile strength cotton stands between silk and wool; 
whereas, in elasticity, it is considerably below either of the other 
two fibres. The breaking strain of cotton will vary from 2.5 
to 10 grams, depending on the fineness of staple; the finer the 
fibre, the less will be its breaking strain. 

Cotton is less hygroscopic than either wool or silk; under 
normal conditions it will contain from 7 to 8 per cent, of hygro- 
scopic moisture, though in a very moist atmosphere this may be 
considerably increased. 

The hygroscopic quality of cotton (and, in fact, other vegetable 
fibres as well) has much to do with its proper condition during 




FtG. 37. — ^Appearance of Cotton Fibre on Treatment with Schweitzer's Reagent. 

(Witt.) 

c, transverse ligatures of disrupted cuticle; b, irregular shreds of cuticle torn apart; 

c, swollen mass of cellulose; d, walls of internal canal. 

the various processes of spinning and finishing. It also has an 
influence on the commercial valuation of the raw material, as 



THE PHYSICAL STRUCTURE AND PROPERTIES OF COTTON. 137 

the amount of hygroscopic moisture varies with atmospheric 
conditions, and it is important to have a normal standard of 
reference (see wool conditioning). Its influence on spinning 
is even greater, and proper conditions of atmospheric moisture 
must be maintained in the spinning-room in order to achieve 
the best results; the spinning properties of raw cotton, however, 
are also affected by other substances associated with the cellulose 
of the fibre, but it is without question that the physical condi- 
tion of cotton is largely influenced by its content of hygroscopic 
moisture, and this should be delicately adjusted by the spinner 
to meet the conditions of his work. The mechanical treatment 
of woven textile materials in finishing processes, such as mangling, 
beetling, calendering, etc., is also dependent for good results to 
quite an extent on the hygroscopic condition of the fibre; the 
amount of moisture present during the finishing operations, 
together with the method and degree of drying, should be care- 
fully studied.* 

The following table shows the results of experiments on 
the tensile strength of different varieties of cotton: 



Cotton. 



Sea-island (Edisto) 

Queensland 

Egyptian , 

Maranham 

Bengal 

Pernambuco 

New Orleans 

Upland 

Surat (Dhollerah). 
Surat (Comptah). . 



Mean Breaking Strain. 



Grains. 



83-9 
147.6 
127.2 
107. 1 
100.6 
140.2 

147-7 
104.5 

141-9 
163-7 



Grams. 



5-45 
9-59 
7.26 
6.96 

6-53 
9. II 
9.61 
6.79 
9. 22 
10.64 



* In testing the influence of moisture on the strength of cotton material, the 
Industrial Society at Mulhause reports as follows: 

Normal strength of cloth 100 

Saturated with moisture 104 

Dried on hot cylinder 86 

Again dampened 103 

It would appear from these results that the alternate moistening and hot dicing 
of cotton caused little or no deterioration in its strength. 



138 



THE TEXTILE FIBRES. 



The full tensile strength of the individual fibre, however, is 
not utilized in the spun yarn. Single yams will give only about 
20 per cent., or one-fifth, of the breaking strain calculated from 
the strength of the separate fibres; two-ply yarns give about 
25 per cent. 

The following table exhibits the comparative values of the 
tensile strength of different fibres. The "breaking length" 
refers to a length of thread which will break by reason of its own 
weight. 



Fibre. 



Breaking Length 
in Kilometers. 



Tensile Strength, 
Kilograms per 
Square mm. 



Cotton 

Wool 

Raw silk 

Flax fibres. .. . 

Jute 

China grass . . 

Hemp 

Manila hemp. 
Cocoanut fibre 
Vegetable silk. 



25.0 
8.3 
33-0 
24.0 
20.0 
20.0 
30.0 
31.8 
17.8 

24-5 



37-6 
10.9 
44.8 
35-2 
28.7 

45 -o 
29.2 



When cotton is purified from its adhering waxy and fatty 
matters, it becomes remarkably absorbent. This quality is 
explained on the supposition that the ripe cotton fibre is made 
up of a series of tissues of cellulose, separated from each other 
by intercellular matter, in this way forming a series of capillary 
surfaces which are capable of exerting considerable capillary 
force upon any liquid in which the fibre may be immersed. Dry 
cotton also appears to be remarkably absorptive of gases; it is 
said that the fibre can absorb 115 times its volume of ammonia at 
the ordinary atmospheric pressure. 



CHAPTER XI. 

CHEMICAL PROPERTIES OF COTTON; CELLULOSE. 

I. Chemical Constitution. — ^In its chemical composition, cot- 
ton, in common with the other vegetable fibres, consists essentially 
of cellulose. On the surface there is a protecting layer of more 
or less wax and oily matter, and also in the fibre there is a trace 
of pigment, which in some varieties of cotton becomes quite 
emphasized. The removal of these substances is the object of 
the boiling- out and bleaching processes to which cotton is sub- 
jected prior to its dyeing and printing. In reaHty, the purified 
cotton fibre as it exists in bleached material is practically pure 
cellulose, and this compound alone appears to be essential to its 
structural organization. 

The natural impurities present in the raw cotton fibre amount 
to about 4 to 5 per cent., and consist chiefly of pectic acid, color- 
ing-matter, cotton-wax, cotton-oil, and albuminous matter. The 
fibre gives about i per cent, of ash on ignition.* The oil present 
in the fibre appears to be identical with cottonseed- oil, and is 
probably obtained from the seed to which the fibre is attached. 
The cotton- wax serves as a protective coating for the fibre and 
makes it water-repellent, as is evidenced by the long time it 
requires for raw cotton to be wetted out by simply steeping in 
water. This wax appears to be closely analogous to camaiiba 
wax ; it is not soluble in alkalies, though it may be gradually emul- 
sified by a long- continued boiling in alkaHne solutions, on which 

* Bowman is of the opinion that considerable stress should be laid on the 
fact that the cotton fibre contains about i per cent, of mineral matter as an integral 
part of its constitution, and this no doubt has considerable influence on its struc- 
ture and properties. 

139 



I40 THE TEXTILE FIBRES. 

fact is based the ' ' boiling-out ' ' of cotton by the ordinary methods. 
Cotton-wax, however, appears to be readily soluble in sulphated 
oils, such as Turkey-red oil, and hence cotton may be rapidly 
and thoroughly wetted out by using a solution of such an oil. 
The coating of wax over the cotton fibre appears to influence its 
spinning qualities to a certain extent, as it requires, for instance, 
a rather elevated temperature to successfully spin fine yarns, in 
order probably to soften the waxy coating of the fibre.* The fatty 
acid present in cotton-wax has been found to be identical with 
margaric acid. The coloring-matter of cotton has been investi- 
gated and has been found to consist of two organic pigments, 
the one easily soluble in alcohol, and the other only dissolved by 
boiling alcohol. According to Schunck, the composition of these 
bodies from Nankin cotton is as follows: 

A. — Soluble in B. — Insoluble in 

Cold Alcohol. Cold Alcohol. 

Per Cent. Per Cent. 

Carbon 58 . 22 57-7° 

Hydrogen . 5 . 42 5 • 60 

Nitrogen 3 . 73 4. 99 

Oxygen 32 . 63 31.71 

The composition of the analogous coloring-matters in American 
cotton is practically identical with the above. 

Pectin compounds form the greater portion of the impurities 
present in cotton, and are probably rather complex in nature. 

According to Dr. Schunck, American cotton contains about 
0.48 per cent, of fatty matters, whereas East Indian cotton con- 
tains only 0.337 P^r cent. 

Analysis of cotton- wax shows it consists of the following: 

Per Cent. 

Carbon 80. 38 

Hydrogen 14 • 5 1 

Oxygen 5. 11 

* As the temperature falls the oily wax tends to become stiff and gummy, 
and prevents the proper drawing of the fibre; while its presence amongst the 
thin laminations of the cell-walls gives a greater elasticity to the fibre, and renders 
it less Uable to sudden rupture. The gradual drying up of the more volatile 
portions of this oil in the fibre, leaving the remaining portion thicker and stiffer, 
may also, and probably does, account for the fact noticed by most spinners, that 
new-crop cotton seems to work better and makes less waste than as the season 
advances. (Bowman, "Cotton Fibre," p. 55.) 



CHEMICAL PROPERTIES OF COTTON; CELLULOSE. 141 

It fuses at 85.9° C, and solidifies at 82° C, hence it bears a 
close analogy to both cerosin, or sugar-cane wax, and carnaiiba 
wax. 

The quantity of ash (mineral matter) in raw bale- cotton will 
average considerably higher than that obtained from the purified 
fibre; this is due to adhering sand and dust which are nearly 
always present. The following table shows the amount of ash 
contained in samples of different varieties of cotton : 

Per Cent. 

Dharwar 4. 16 

Dhollerah 6.22 

Sea-island i . 25 

Peruvian (soft) i . 68 

" -(rough) 1. 15 

Bengal 3 . 98 

Broach 3 . 14 

Oomrawuttee 2.52 

Egyptian (brown) i . 73 

" (white) 1 . 19 

Pernam i . 60 

American 1.52 

When the amount of ash is found to be over i per cent, the 
excess may be considered as mechanically attached sand and 
dust. The true ash of the cotton fibre consists principally of 
the carbonates, phosphates, chlorides, and sulphates of potassium, 
calcium, and magnesium, as is exhibited by the following analysis 
of Dr. Ure: 

Per Cent. 

Potassium carbonate 44 . 80 

" chloride 9 ■ 9° 

" sulphate 9 • 3° 

Calcium phosphate 9 . 00 

" carbonate 10. 60 

Magnesium phosphate 8 . 40 

Ferric oxide 3 • 00 

Alumina and loss 5 • 00 

The analyses of Davis, Dreyfus, and Holland, reported as a 
mean from twelve different varieties of cotton, show a little 
difference from the above analysis, especially in having present 
sodium carbonate as one of the constituents. The mean of 
these analyses is given as follows: 



142 THE TEXTILE FIBRES. 

Per Cent. 

Potassium carbonate 33-22 

" chloride 10.21 

" sulphate 13 • 02 

Sodium carbonate 3-35 

Magnesium phosphate 8-73 

" carbonate 7.81 

Calcium carbonate 20. 26 

Ferric oxide 3-40 

The albuminous or nitrogenous matter present in cotton 
is only of very small amount, and doubtless consists of protoplas- 
mic residue. Different varieties of cotton, on analysis, show 
the following percentages of nitrogen; some of this, however, 
may be derived from mineral nitrates which may be present in 
slight amount in the fibre (Bowman): 

Per Cent Nitrogen. 

American o . 030 

Sea-island o. 034 

Bengal o . 039 

Rough Peruvian o. 033 

Egyptian (white) c. 029 

" (brown) o . 042 

Mean o . 0345 

Analyses conducted by the U. S. Department of Agriculture 
give the average amount of nitrogen present in cotton as 0.34 pel 
cent. As this differs very considerably from that obtained by 
Bowman, it may be possible that the latter must be multiplied 
by ten to obtain the correct figure. 

Church and Miiller have made careful analyses of raw cotton 
with the following results: 

I. II. 

Cellulose 91 -15 91-35 

Hygroscopic water 7-56 7 . 00 

Wax and fat 0.51 0.40 

Nitrogen (protoplasm) 0.67 0.50 

Cuticular tissue o. 75 

Ash o.ii 0.12 

2. Cellulose. — ^This is one of the most important of the natu- 
rally occurring chemical compounds, as it forms the basis of all 
vegetable tissue. Chemically it consists of carbon, hydrogen. 



CHEMIC/IL PROPERTIES OF COTTON; CELLULOSE. 143 

and oxygen, and has the empirical formula CeHioOg. It belongs 
to a class of bodies known as carbohydrates, and is closely related 
to the starches, dextrins, and sugars. Chemically considered, 
these compounds must all be regarded as alcohols containing 
aldehydic and ketonic groups. The word cellulose must not 
be taken as signifying a simple definite substance of unvarying 
properties, but rather as a generic term including quite a number 
of bodies of similar chemical nature. Like starch and other 
complex carbohydrates of organic physical structure, cellulose 
will vary somewhat in its properties, depending upon its source 
or derivation. As a class the celluloses exhibit certain chemical 
characteristics, by means of which they may be distinguished 
from associated bodies of allied chemical constitution. Physically 
they are colorless amorphous substances capable of withstanding 
rather high temperatures without decomposition. They are 
insoluble in nearly all of the usual solvents, but dissolve more 
or less completely in an ammoniacal solution of copper oxide 
(Schweitzer's reagent). Solution in this latter reagent apparently 
takes place without decomposition, as the cellulose may be repre- 
cipitated unchanged therefrom by the addition of acids and 
various salts. In order to obtain pure cellulose for chemical 
purposes it is customary to treat cotton successively with dilute 
caustic alkaU, dilute acid, water, alcohol, and ether. The pur- 
pose of this treatment is to remove all foreign and encrusting 
materials from the raw fibre, and possibly also to remove the 
thin, external cuticular membrane which may be chemically 
different from the rest of the tissue. The specific gravity or 
density of cellulose as obtained in the usual manner is about 1,5, 
and this also represents the density of cotton and most other 
plant fibres. Chemically considered, cellulose is a derivative 
of the open chain or paraffin series of hydrocarbons, and further- 
more it exhibits the reactions of a saturated compound. As 
with the other carbohydrates, chemists have found it a matter 
of great difficulty to ascertain even approximately the true mo- 
lecular formula of cellulose. Though its empirical formula is 
CgHioOs, this in no way represents the true molecular complexity 
of the substance. From a study, however, of its various synthet- 



144 THE TEXTILE FIBRES. 

ical derivatives, with special reference to its esters, such as the 
acetates, benzoates, and nitrates, the provisional formula of 
C, H20O10 has been given to the cellulose molecule. The nature 
and position of the various organic groups present in this mo- 
lecular formula, however, has yet to be worked out.* 

In its chemical reactions cellulose is particularly inert, com- 
bining with only a few substances, and then only with great diffi- 
culty and under peculiar conditions. It is quite resistant to the 
processes of oxidation and reduction, and hydrolysis and dehy- 
dration. Concentrated sulphuric acid dissolves cellulose with 
the production of a viscous solution; dilution with water causes 
the precipitation of an amorphous substance known as amyloid, 
a starch-like body having the formula C^^^O-^^^, and like starch 
it is colored blue with iodine. On this reaction is based 
the method of testing for cellulose, by applying sulphuric acid 
and iodine. On boiling with dilute sulphuric acid., cellulose is 

* Vignon has proposed to give cellulose the following constitutional formula: 

O CH\ 

I \ 
O ^(CHOH)3. 

• CH2— CH^ 

This is based on a study of the highest nitrate of cellulose and the decomposi- 
tion of the nitrate by alkalies with formation of hydroxypyruvic acid. The struc- 
ture given, however, is more or less hypothetical in nature, and needs experimental 
confirmation in many particulars before it can be accepted without question. 
The older chemical configuration of cellulose given by Bowman, 

H H H 

I I I 

H— C— C= C=C— C— C— H, 

OH OH OH OH OH 

is without any experimental reason for its- existence, and the idea that it contains 
an unsaturated carbon grouping, — C=C — , has been proved erroneous. From 
a study of the osazones of oxycellulose, Vignon has ascribed to this latter body 
the constitutional formula of the group, 

/COH 
(CHOH)/ 

\CH— CO, 
\/ 

o 

in union with varying proportions of residual cellulose. 



CHEMICAL PROPERTIES OF COTTON; CELLULOSE. I45 

converted into dextrin and glucose. On heating with acetic 
anhydride to i8o° C, cellulose is converted into an acetyl deriva- 
tive having the formula Ci2Hi404(OCOCH3)6. By the moderated 
action of concentrated acids and various acid salts, cellulose 
appears to undergo a process of hydration, being converted into 
a friable amorphous body known as hydrocellulose. This reac- 
tion is of importance in the carbonizing process for removing 
vegetable matter from woolen goods. • 

A concentrated solution of zinc chloride will dissolve cellulose 
on heating and digesting for some time. This solution has been 
employed industrially for the preparation of cellulose filaments 
which are subsequently treated with hydrochloric acid and 
washed for the purpose of removing the zinc salt; the thread is 
then carbonized and is employed for the carbon filament of incan- 
descent electric lamps. A concentrated solution of zinc chloride 
in hydrochloric acid dissolves cellulose quite rapidly and in the 
cold. This latter method is useful in the laboratory for the study 
of celluloses, but as yet has received no technical appHcation. 
By means of this solution it has been shown that the cellulose 
molecule does not contain any unsaturated carbon groups, for 
it exhibits no absorption of bromine. A solution of a ligno- 
cellulose, on the other hand, gives a marked bromin absorption, 
thus showing evidence of unsaturated carbon groups. 

Cellulose is colored a deep violet by a solution of zinc chlor- 
iodide, and this reagent is employed as a delicate test for the 
presence of cellulose. The reagent may be best prepared by 
using 90 parts of a concentrated solution of zinc chloride, adding 
6 parts of potassium iodide in 10 parts of water, and iodin until 
saturated. 

When cellulose is treated with concentrated caustic alkahes 
it undergoes a change which may be crudely referred to as " mer- 
cerization," whereby a compound known as alkali-cellulose is 
formed, in which the molecular ratio of alkah to cellulose may 
be given as C^jHjoOio :NaOH. When this body is treated with 
carbon disulphide a substance known as cellulose thiocarhonate or 
xanthate is formed. This body yields a very viscous solution 
with water and has been utiHzed for various technical purposes 



146 THE TEXTILE FIBRES. 

(see viscose). Cellulose xanthate undergoes spontaneous decom- 
position, splitting up into cellulose hydrate, alkali, and carbon 
disulphide; this cellulose hydrate is also known as regenerated 
cellulose. This substance can also be precipitated by the 
addition of various salts, such as ammonium chloride. Alkali- 
cellulose also reacts with benzoyl chloride with the formation of 
cellulose benzoate. Another ester of cellulose is the acetate, which 
can be made by the action of acetic anhydride on cellulose heated 
in a sealed tube; regenerated cellulose can also be employed. 
By varying the conditions of treatment a number of different 
acetates have been prepared. The tetracetate has received a 
number of commercial applications for the production of films 
and for waterproofing. By the action of nitric acid under vary- 
ing conditions a number of cellulose nitrates (improperly called 
nitrocelluloses) have been prepared, which have received numer- 
ous appHcations (see pyroxylin). Concentrated sulphuric acid 
reacts with cellulose to form at first a cellulose sulphate; this 
subsequently undergoes decomposition with a consequent hy- 
drolysis of the cellulose molecule and the formation of amy- 
loid. 

Although cellulose is comparatively inert to the majority of 
chemical reagents, it has a powerful attraction for certain salts 
held in solution and will absorb them completely. This power 
of absorption is especially marked towards salts of vanadium, 
these being completely separated from solutions containing only 
one part of the salt in a trillion. 

Besides cellulose itself, there are a number of derived sub- 
stances which are known as compound celluloses. These are 
classified into three general groups: 

{a) Pectocelluloses, related to pectin compounds of vegetable 
tissues; represented among the fibres by raw flax; resolved by 
hydrolysis with alkalies into pectic acid and cellulose. 

(&) Lignocelhiloses, forming the main constituent of woody tis- 
sue and represented among the fibres by jute; resolved by chlorina- 
tion into chlorinated derivatives of aromatic compounds soluble 
in alkalies and cellulose. 

(c) Adipocelluloses, forming the epidermis or cuticular tissue 



CHEMICAL PROPERTIES OF COTTON; CELLULOSE. 147 

of fibres, leaves, etc.; resolved by oxidation with nitric acid into 
derivatives similar to those of the oxidation of fats and cellulose. 

Fremy groups the various celluloses and their derived bodies 
in the following manner, which is based on a chemical classifica- 
tion: (a) celluloses, including normal cellulose, paracellulose, and 
metacellulose ; {h) vasculose (identical with lignocellulose) ; (c) 
cutosc; (d) pectose. 

3. Chemical Reactions of Cotton.— Cotton itself presents the 
same general reactions and chemical properties as cellulose. It 
is capable of standing rather high temperatures without decom- 
position or alteration; though it appears that when cotton is sub- 
jected to a temperature of 160° C, whether moist or dry heat, 
a dehydration of the cellulose takes place, accompanied by a 
structural disintegration of the fibre. This fact has an important 
bearing on the singeing, calendering, and other finishing processes 
where high temperatures are used. At 250° C. cotton begins to 
turn brown ; and when ignited in the air it burns freely, emitting 
an odor faintly suggesting acrolein, but without the characteristic- 
ally empyreumatic odor of burning animal fibres. When sub- 
jected to dry distillation cotton is decomposed into methane, 
ethane, water, methyl alcohol, acetone, acetic acid, carbon dioxide, 
pyrocatechol, etc. Though unaltered and insoluble in boiling 
water, when heated with water under pressure to 200° C. it is 
dissolved with complete decomposition. 

Like cellulose itself, cotton is dissolved by Schweitzer's reagent, 
though under ordinary conditions its solution is a rather slow 
process. In order to dissolve cotton most effectively in ammonia- 
cal copper oxide, it is recommended to treat the raw cotton with a 
strong solution of caustic soda until the fibres swell up and become 
translucent ; squeeze out the excess of liquid, and wash the cotton 
with strong ammonia water; then treat with the solution of 
ammoniacal copper oxide and the cotton will be found to dissolve 
quite rapidly. This solution may furthermore be filtered and 
diluted with water. The use of this solution for the production 
of lustra-cellulose filaments has received some degree of com- 
mercial application (see Pauly silk). This reaction is also util- 
ized in the production of the so-called Willesden canvas; the 



148 THE TEXTILE FIBRES. 

cotton fabric is passed through a solution of ammoniacal copper 
oxide, whereby the surface becomes coated with a film of par- 
tially dissolved gelatinized cellulose containing a considerable 
amount of copper oxide. On subsequent hot pressing this film 
is fixed on the surface of the material as a substantial coating, 
which is said to make the canvas water-proof and render it un- 
affected by mildew and insects. 

Concentrated solutions of zinc chloride are capable of dis- 
solving cotton, but only after a prolonged digestion at about 
100° C, though by first treating the cotton with caustic alkali 
the solution takes place in the cold. The product so obtained 
has received several industrial apphcations; vulcanized fibre is 
prepared by dissolving paper in a concentrated solution of zinc 
chloride, and the resulting gelatinous mass is manufactured 
into various articles, such as blocks, sheets, etc. The chief 
difficulty encountered is the subsequent removal of the zinc salt, 
which necessitates a very lengthy process of washing. The ma- 
terial may be rendered water-proof by a further process of nitra- 
tion.* The solution has also been suggested for use as a thick- 
ening agent in calico-printing. Its use for the production of 
lustra- cellulose or artificial silk and incandescent lamp filaments 
has also been attempted. 

With mineral acids cotton exhibits practically the same gen- 
eral reactions as pure cellulose. Concentrated sulphuric acid 
produces amyloid in the manner already mentioned, and this 
fact is utiHzed in the preparation of what is known as vegetable 
parchment. Unsized paper is rapidly passed through concentrated 
sulphuric acid, then thoroughly washed and dried. The effect of 
this treatment is to cause the formation on the surface of the 
paper of a layer of gelatinous amyloid, which on subsequent 
pressing and drying gives a tough membranous surface to the 
paper resembling true parchment. This renders the paper grease- 
proof and water-proof, and increases its tensile strength con- 
siderably. Ariifi-cial horse-hair has been prepared in a similar 
manner from certain Mexican grasses. These latter are steeped 
for a short time in concentrated sulphuric acid, and become 



* Hofmann, Handb. d. Papierfab., p. 1703. 



CHEMICAL PROPERTIES OF COTTON; CELLULOSE. 149 

parchmentized thereby, so that on being subsequently washed 
and combed they assume an appearance very much resembhng 
horse-hair, and are said to possess even greater elasticity than 
horse-hair itself. In place of strong sulphuric acid a solution of 
zinc chloride may be used with similar results. Amyloid appears 
also to be a product of natural plant growth, as its presence has 
been detected in the walls of vegetable cells; it may be recog- 
nized by giving a blue color with iodine. 

Very dilute solutions of sulphuric acid, especially in the cold, 
have no appreciable action on cotton. But if the fibre is impreg- 
nated with such a solution and then allowed to dry it becomes 
rapidly tendered; this is owing to the gradual concentration 
of the acid in the fibre on drying. Elevated temperatures also 
cause the dilute acid to attack the fibre much more quickly and 
severely than otherwise. 

In all dyeing and bleaching operations where the use of acid 
may be required the above facts should always be borne in 
mind; the temperature of the acid baths should not be above 
70° F., and the acid strength should not be more than 2 per 
cent. Where higher temperatures are necessar}^ organic acids 
should be substituted for mineral acids wherever possible. Acetic 
acid, for instance, is often used. Whenever cotton is treated 
with acid solutions or with salts of an acid nature or which are 
liable to decompose with liberation of acid, all of the acid should 
be removed from the fibre or properly neutrahzed before drying, 
else the material will be tendered and probably ruined. The 
action of dilute acid on cotton is probably an hydrolysis of the 
cellulose molecule, with the formation of hydroxycellulose, causing 
a structural disorganization of the fibre to take place. Hydro- 
chloric acid has an effect similar to sulphuric acid, and the same 
remarks concerning the use of this latter acid in connection 
with cotton also hold true for the former. Strong nitric acid has 
a somewhat different effect ; * it completely decomposes cotton, in 



* The action of nitric acid on cotton fabrics appears to be a peculiar one. The 
following observations in this respect have been recorded by Knecht: Bleached 
calico steeped for fifteen minutes in pure nitric acid at 80° Tw., washed and dried 
showed a considerable contraction, amounting to about 24 per cent.; the tensile 



150 THE TEXTILE FIBRES. 

common with other forms of cellulose, oxidizing it to oxalic 
acid. When boiled with moderately concentrated nitric acid 
cotton is converted into oxycellulose, a structureless, friable 
substance possessing a great affinity for basic dyestuffs. When 
mixed with concentrated sulphuric acid, however, the action 
of nitric acid is totally different, the cellulose being converted 
into a nitro-derivative, though the physical appearance of the 
fibre is not appreciably altered. The exact nature of the nitrated 
compound will depend on the conditions of treatment. Several 
nitrocelluloses are known and possess commercial importance; 
they are classified under the general name of pyroxylins. Gun- 
cotton, a hexanitrocellulose, is the most highly nitrated product, 
and is used as a basis of many explosives. Soluble pyroxylin is 
a trinitrocellulose ; its solution in a mixture of alcohol and ether 
is called collodion and is employed in surgery and photography. 
Another derivative, supposed to be a tetranitrocellulose, is also 
soluble in ether-alcohol, and its solution has been utilized 
for the production of lustra-cellulose filaments. By dissolving 
nitrocellulose in molten camphor a substance known as celluloid 
is formed. 

The action of hydrofluoric acid on cotton and other vegetable 
fibres appears to be a peculiar one; a transparent, tough, flexible 
water-proof material being obtained. The product does not 
appear to resemble parchment obtained by the action of sulphuric 
acid. It is used as an insulating material and for making the 
carbon filaments of incandescent electric lamps. 

Organic acids in solution, even when moderately concentrated, 

strength also increased 78 per cent. Unbleached yarn, treated in the same manner, 
also showed a considerable increase of tensile strength, and a proportional con- 
traction in length. Weaker acids did not show these results, the fibre being 
tendered instead of being strengthened. Analysis proved that 7.7 per cent, of 
nitrogen was present, showing that about two molecules of the acid had combined 
with the cotton. The shrinkage, gain in strength, microscopical appearance, 
etc., of the treated material, all go to show that in addition to the nitration a mer- 
cerizing effect has been produced. This appears in the fact that the material 
exhibits a strongly increased affinity for many dyestuffs, especially the direct 
cotton colors and some of the acid dyes ; while by reason of its not showing any 
increased affinity for the basic colors there is proof that oxycellulose has not 
been produced. 



CHEMICAL PROPERTIES OF COTTON; CELLULOSE. 151 

do not appear to have any injurious action on cotton. The non- 
volatile acids, however, such as oxalic, tartaric, and citric acids, 
when allowed to dry into the fibre, act much in the same manner 
as mineral acids, especially at elevated temperatures.* Acetic 
acid, however, being volatile, exerts no destructive action; hence 
this latter acid is particularly suitable for use in the dyeing and 
printing of cotton goods, where the use of an acid is requisite.! 

Tannic acid, unlike other acids, exhibits quite an affinity for 
cotton, the latter being capable of absorbing as much as 7 to 10 
per cent, of its weight of tannic acid from an aqueous solution. 
Advantage is taken of this fact in the mordanting of cotton with 
tannic acid and tannins for the dyeing and printing of basic 
colors. Cotton exhibits a similar attraction for tungstic acid; 
the expense of this latter compound, however, precludes its 
adoption as a mordanting agent. 

Though acids, in general, have such an injurious action on 
cotton, alkalies, on the other hand, are harmless under ordinary 
conditions. Dilute solutions of either the carbonated or caustic 
alkalies, even at a boiling temperature, if air is excluded, have 
no injurious effect on cotton. In the presence of air alkaline 
solutions cause an hydrolysis of the cellulose in a manner similar 
to acids, with the result that the fibre is seriously weakened. 
This action of alkalies in the presence of air is an important 
one to bear in mind in the operations of bleaching, dyeing, or 
mercerizing which will be subsequently studied. Boihng solu- 

* The destructive action of these acids on the cotton fibre is, perhaps, not 
so much of a chemical nature as mechanical, it being caused by the acids crystal- 
lizing within the fibre and thus breaking the cell-wall. A dry heat, for instance, 
in connection with these acids is much more injurious than a moist heat, a fact 
which is of much importance in the drying of cotton prints, where the above- 
mentioned acids may have been used. 

t Oxalic acid appears to have a pecuHar effect on cotton; it has been noticed 
that if a piece of cotton cloth be printed with a thickened solution of oxalic acid, 
dried, and hung in a cool place for about twelve hours, and then well washed, 
the printed parts exhibit a direct affinity towards the basic dyes. The cotton 
so treated does not become tender or otherwise changed. Towards substantive 
dyes it exhibits considerably less attraction than ordinary cotton, while with alizarin 
dyes it is partially reactive. Tartaric and citric acids do not produce the same 
effect, nor does the neutral or acid oxalate of potassium. 



152 



THE TEXTILE FIBRES. 



tions of dilute alkalies dissolve or emulsify the waxy and fatty 
impurities encrusting the cotton fibre, hence these reagents are 
largely employed in the scouring of cotton goods. 

The action of alkaline solutions at high temperatures (above 
ioo° C.) on cotton appears, however, to be a destructive one. 
Tauss has shown that if cotton be digested with solutions of 
caustic soda under pressure, the fibre is attacked and converted 
into soluble products; the degree of decomposition depending 
on the pressure and the strength of the alkaline hquor, in accord- 
ance with the following table: 



Pressure. 


Strength of Alkali. 


3% NaaO. 


8% NaaO. 


Per Cent Dissolved. 




12. I 

15-4 
20.3 


22.0 
58.0 
59-0 


<. atmospheres 







Solutions of ammonia do not act on cotton until quite high 
temperatures are reached. According to the experiments of L. 
Vignon, at 200° C. ammonia reacts with cotton cellulose, the 
result being the evident formation of an amidocellulose com- 
pound, the product evincing a greatly increased degree of absorp- 
tion for dyestuff solutions, especially for the acid coloring-matters, 
somewhat after the manner of animal fibres. 

This action of alkaline solutions on cotton under high pressure 
has an important bearing on the bleaching of this fibre, where it 
is subjected to such action by boiling with alkalies in pressure 
kiers. This phase of the question does not appear to have re- 
ceived much attention from either the practical bleacher or the 
theoretical chemist, but it would seem to be worthy of some degree 
of intelKgent research on the part of both. 

Concentrated solutions of caustic alkalies have a peculiar 
effect on cotton; the fibre swells up, becomes cylindrical and 
semi-transparent, while the interior canal is almost entirely oblit- 
erated by the swelling of the cell-walls. There is a marked gain 



CHEMIC/IL PROPERTIES OF COTTON; CELLULOSE. 153 

in weight and strength, while the affinity of the cotton for coloring- 
matters is materially increased. This effect was first noticed by 
John Mercer in 1844, and the reaction forms the basis of the 
modem process of mercerizing, under which title a more com- 
plete and extensive discussion of this reaction will be found. 
Solutions of sodium sulphide appear to have no immediate ten- 
dering action on cotton, even at a boiling temperature. If the 
sodium sulphide is dried into the fibre after about six weeks the 
cotton shows a loss in strength of from 10 to 20 per cent. Also, 
when sodium sulphide is dried in the fibre at 100° C, the tender- 
ing amounts to from 10 to 20 per cent. Cotton containing copper 
sulphide or iron sulphide shows no appreciable amount of tender- 
ing. When cotton is impregnated with sulphur and exposed to a 
damp atmosphere for several weeks its tensile strength is reduced 
by about one-half. This is perhaps due to the oxidation of the 
sulphur into sulphurous and sulphuric acids. 

If cotton, or other forms of cellulose, be treated with a concen- 
trated solution of caustic soda to which a small amount of carbon 
disulphide has been added, the fibres swell up, become disinte- 
grated, and finally form a gelatinous mass. This latter is 
soluble in a large amount of water, producing a very viscous 
solution, technically known as viscose. From this solution hydro- 
cellulose may be precipitated by sulphurous acid gas, as well as 
by various other reagents. Precipitation also occurs by simply 
allowing the solution to stand for some time, in which case the 
hydrocellulose separates out as a jelly-like mass. Viscose has 
received several commercial applications, among which may be 
mentioned more especially the use of its solutions for the prepara- 
tion of lustra-cellulose filaments. 

Though cotton does not show nearly the same degree of affin- 
ity for acids and alkahes as do the animal fibres, nevertheless it 
has been shown that cotton does absorb both acids and alkahes 
from their solutions, even when cold and dilute. The ratio of 
absorption appears to be 3 molecular parts of acid to 10 molecular 
parts of caustic alkali. Vignon, by a study of the thermochem- 
ical reactions of cotton, has shown that when this fibre is treated 
with acids or alkalies a liberation of heat takes place, from which 



154 THE TEXTILE FIBRES. 

fact it would appear that cotton exhibits in some degree the 
properties of a very weak acid and a still weaker base. 

Strong oxidizing agents, such as chromic acid, permanganates, 
chlorin, etc., in concentrated solutions, readily attack cotton, 
converting it into oxycellulose. This substance appears to pos- 
sess an increased affinity for dyestuffs, but it is of a structureless 
and brittle nature, hence its formation greatly tenders the fibre. 
It is said that oxycellulose is indifferent towards the tetrazo 
dyestuffs; and, in consequence, these may be employed for the 
purpose of detecting the presence of oxycellulose in cotton mate- 
rials. 

In its action towards various metallic salts cotton is very neu- 
tral, thereby differing considerably from both wool and silk. If 
the salts, however, are present in a very basic condition, cotton 
is capable of decomposing them and loosely fixing the metallic 
hydroxide. Many salts, especially those of an acid nature, will 
tender the cotton fibre, probably due to the liberation and drying 
in of the acid. Consequently such salts should be avoided or 
used very carefully with cotton, and any excess should be thor- 
oughly eliminated by subsequent washing before the material 
dries. 

In its behavior towards coloring-matters cotton differs most 
markedly from the animal fibres. Of the natural dyestuffs, only 
a few color the cotton fibre without a mordant; with the coal-tar 
colors, cotton exhibits no affinity for most of the acid or basic 
dyes, and these can only be apphed on a suitable mordant. The 
substantive colors, however, are readily dyed on cotton, in a 
direct manner, and since their introduction the methods of cotton 
dyeing have been practically revolutionized. 

Though resistant to the action of moths and insects in general, 
cotton is liable to undergo fermentation, as is evidenced by the 
formation of mildew on cotton fabrics stored in damp places. 
Though this fermentation is often induced by the presence of 
more or less starchy matter contained in the sizing materials 
used in finishing the goods, yet pure cellulose itself can also be 
fermented, and Omeliansky has succeeded in isolating the par- 
ticular bacillus which destroys cellulose. 



CHEMICAL PROPERTIES OF COTTON; CELLULOSE. 



155 



There has been much discussion as to whether the various 
treatments to which cotton is subjected during the process of 
bleaching has any deleterious effect on the strength of the fibre. 
In this connection O'Neill gives the following interesting results, 
made to determine the tensile strength of cotton threads before 
and after bleachins : 



Average Weight Required to Break 
a Single Thread. 



Before Bleaching. 



After Bleaching. 



No. I cloth, weft-threads. 
No. I " warp-threads. 
No. 2 " 
No. 2 " " 



1 7 14 grains 
3140 " 
3407 " 
3512 " 



2785 grains 
2020 " 
3708 " 
4025 " 



It will be noticed that in two cases out of three the warp-threads 
are stronger than before, and it may be safely concluded that the 
tensile strength of cotton yam is not injured by careful though 
thorough bleaching, and probably it may be strengthened by the 
wetting and pressure causing a more complete and effective bind- 
ing of the separate cotton fibres, the twisting together of which 
makes the yam stronger. 



CHAPTER XII. 

MERCERIZED COTTON. 

I. Mercerizing is a term applied to that process whereby 
cotton is treated with concentrated caustic alkahes. In its 
strictest significance, however, it refers most directly to the 
process of giving cotton a high degree of lustre by subjecting it 
simultaneously to the chemical action of caustic alkalies and the 
mechanical action of strong tension sufficient to prevent con- 
traction. The process is named from John Mercer, who first 
discovered the effect of strong solutions of caustic alkalies on 
cotton in the year 1844. It was not until the last decade, how- 
ever, that the process attained any -degree of commercial success; 
but during the last few years it has given practically a new fibre 
to the textile industry. 

Mercerizing, in its essential meaning, relates to the action of 
certain chemicals on cellulose whereby the latter is changed to 
a product known as cellulose hydrate; though, technically, the 
term has come to mean the process concerned with the imparting 
of a silk-like lustre to the fibre. As generally understood, it 
consists briefly in impregnating cotton yarn or cloth with a rather 
concentrated cold solution of caustic soda and subsequently 
washing out the caustic liquor with water, the material being 
either held in a state of tension during the time it is treated with 
the caustic alkali in order to prevent contraction, or stretched 
back to its original length after treatment wth the alkali, but 
previous to washing. In either case, the material must be in a 
state of tension during the process of washing. There are two 
separate phases of the mercerizing process represented in the 

156 



MERCERIZED COTTON. 157 

above operations which must be separately understood in order 
to comprehend the exact nature of the change which takes place 
in the appearance of the fibre; the one is the chemical action of 
the caustic soda, and the other is the mechanical effect brought 
about by the tension. The action of the caustic alkali is to effect 
a chemical transformation in the substance of the fibre, a further 
chemical reaction taking place when this product is treated with 
water. As already pointed out (p. 145), cellulose has the prop- 
erty of combining with caustic soda to form a product known as 
alkali-cellulose, C^jHjoO^o : NaOH. The formation of this com- 
pound does not appear to disintegrate the organic structure of 
the fibre-cell, provided the proper conditions are maintained. 
The alkali-cellulose, however, is apparently a rather feebly com- 
bined molecular aggregate, and does not exhibit much stability 
towards reagents in general. It is even decomposed by the action 
of water, the effect of the latter being to disrupt the bond of molec- 
ular union between the alkali and cellulose, with the consequent 
re-formation of caustic soda and the introduction of water into the 
cellulose molecule. This latter substance, which may be termed 
cellulose hydrate, forms the chemical basis of mercerized cotton. 
The theory that caustic soda effects a true chemical combination 
with cellulose is somewhat supported by the fact that mercerized 
cotton undergoes chemical changes to which ordinary cotton is 
not susceptible. For instance, the former is much more readily 
dissolved by a solution of ammonio-copper oxide; it is chem- 
ically reactive with carbon disulphide with the formation of 
soluble cellulose thiocarbonates ; alkali- cellulose also reacts with 
benzoyl chloride and acetic anhydride, giving rise to cellulose 
benzoates and acetates. The nature of the chemical change from 
ordinary to mercerized cotton, however, is rather ill-defined; 
it no doubt can be included under that class of reactions which 
stands somewhat midway between ordinary physical and chem- 
ical changes, and is to be particularly observed in connection 
with those bodies possessing a high degree of molecular com- 
plexity, such as various colloidal substances, and the large num- 
ber of naturally occurring carbohydrates, starches, gums, etc. 
The fact that there is no evidence of disorganization in the fibre- 



158 THE TEXTILE FIBRES. 

cell, as may be observed from its physical properties and micro- 
scopic appearance, is a strong argument against true chemical 
change, which would necessitate a rearrangement in the atomic 
grouping in the substance of the fibre. This would result in a 
decomposition of its organized structure, which would at once 
be manifested in a decrease in the tensile strength, and a gradual 
breaking down of the fibre itself. But mercerized cotton shows 
no such change; on the other hand, its tensile strength is con- 
siderably increased, and the fibre-cell shows no tendency towards 
physical decomposition. 

When the cotton fibre is immersed in a concentrated solution 
of caustic soda it undergoes a peculiar physical modification; it 
appears to absorb the alkali, swelling up to a cylindrical form, so 
that it presents more the appearance of a hair than a flat ribbon ; 
the fibre also untwists itself and becomes much straighter, at 
the same time shrinking considerably in length. The internal 
portion of the fibre acquires a gelatinous appearance, becom- 
ing somewhat translucent to light, though it is firm in structure; 
the external surface of the fibre shows a wrinkled appearance 
transversely, due to a somewhat unequal distension of the inner 
part. There is a small degree of lustre on portions of the surface,, 
but, due to the uneven stretching and wrinkling of the external 
superficies, the smooth lustrous portions are irregular in occur- 
rence and not very extensive in area. The fibre also shows a 
slight increase in weight. These changes in the physical appear- 
ance of the fibre are accompanied by a remarkable increase in 
the tensile strength, amounting in most cases to as much as 30 to 
50 per cent.; the fibre also acquiring a greater power of absorp- 
tion towards many solutions, most notably those of dyestuffs. 
The increase in tensile strength is probably due to the fact that 
mercerizing causes the inner structure of the fibre to become 
more solidly bound together by a filling up of the interstitial 
spaces between the molecular components of the cell-wall. In 
this manner the fibre as a whole is given a greater degree of 
solidity; the internal strain between the cell elements (which 
must be quite considerable after the drying out and shrinking 
of the ripened fibre) is lessened no doubt, and hence adds to the 



MERCERIZED COTTON. 159 

unified strength of the fibre. From the fact that the fibre shrinks 
in length in mercerizing, it is probable that the cell elements have 
contracted transversely on the collapse of the fibre canal, and 
on being distended again by the action of the caustic alkali 
these cell elements become shortened longitudinally, and are 
more tightly packed together. The increased affinity for dye- 
stuffs exhibited by mercerized cotton is not to be considered a 
new inherent property of the modified cellulose induced by a 
change in its chemical composition. It is no doubt a result of 
the modified physical structure of the fibre itself; that is, when 
the cell elements have become distended, like a sponge they have a 
greater power of absorption and retention of liquids than when 
in a flattened and collapsed condition. 

The high lustre imparted to the cotton by mercerizing is brought 
about by, other conditions than the mere action of the caustic 
alkali.* In the swelling of the cell-walls and consequent con- 
traction of the fibre, the surface remains wrinkled and uneven, 
due to the unequal strain of expansion. If, however, the ends of 
the fibre are fixed, and thus prevented from contracting when 
subjected to the chemical action of the alkali, the swelling of the 
cell-walls will cause the surface to become smooth and even, and 
capable of reflecting light with but little scattering of the rays, 
similar to a polished surface. Another condition which also 
has much to do with the production of the lustrous appearance 
is no doubt to be found in the physical modification of the cell 
elements thernselves. When the fibre swells up under the action 
of the caustic alkali, its substance becomes gelatinous and trans- 
lucent, and- this has a marked effect on the optical properties of 
the fibre, and enhances the lustre considerably by lessening the 
proportion of light absorbed.f 

* It has been claimed that the mercerizing effect may be obtained without 
tension by the addition of glucose to the alkaline bath. The addition of other 
substances, such as ether, aluminium chloride, etc., have been claimed to pro- 
duce the same result. But it is to be doubted whether a high lustre is obtained 
by any of these methods. 

I Dr. Frankel has advanced the opinion that the high lustre exhibited by 
mercerized cotton is mainly due to the fibre having lost its thin cuticle during 
the process. But this theory is overthrown by the fact that if mercerized cotton 



i6o THE TEXTILE FIBRES. 

Considerable difference is to be obser^^ed in tlie strength 
and elasticity of cotton mercerized without tension and that 
mercerized with tension. Buntrock, in a research on this point, 
found that cotton yarn mercerized without tension showed an 
increase of 68 per cent, in its tensile strength,* whereas the same 
cotton mercerized under tension gave an increase of only 35 
per cent. With respect to the elasticity of the yarn, the same 
chemist ascertained that the untreated cotton employed in his 
experiments stretched 1 1 per cent, of its length before breaking; the 
amount for cotton mercerized without tension was 17 per cent., an 
increase of 54 per cent. ; cotton mercerized under tension showed 
no increase in elasticity at all, and could only be stretched the 
original 11 per cent, before breaking. These figures, of course, 
are not absolute for all varieties of cotton, but will vary within 
considerable limits, depending upon the character of the raw 
cotton employed. Attention must also be drawn to the fact 
that the figures for the tensile strength and elasticity quoted above 
were obtained by using spun yarn and are not based on the single 
fibre. Of course it is the strength of the yarn which is desired in 
practice, but the figure for this is not necessarily that for the fibre 
itself. In mercerizing yarn or cloth, it must be borne in mind 
that the fibres shrink considerably, and in doing so become more 
closely knit together; therefore the increase in tensile strength, as 
ascertained by Buntrock, represents really the greater coherence of 
the fibres to one another, rather than an increase in the strength 
of the individual fibre, because in breaking a yarn spun from a 
large number of fibres there is little or no actual breaking of the 
fibres themselves, but only a pulling apart of the latter. The 
same criticism also applies to a determination of the elasticity. 
It would, perhaps, be more scientific to determine the breaking 

is again subjected to the action of cold strong caustic soda it contracts nearly 
as much as raw cotton would do, and loses its silky lustre entirely. 

* Grosheintz gives the following results of some experiments on the effect of 
mercerization on the tensile strength of cotton. Unmercerized yarn broke with a 
load of 356-360 grams; same yarn mercerized in cold aqueous caustic soda {2,^° B.) 
broke with 530-570 grams; same yarn mercerized with cold alcoholic caustic 
soda (10 per cent.) broke with 600-645 grams; same (except that hot alcoholic 
caustic soda was used) broke with a load of 690-740 grams. 



MERCERIZED COTTON. l6l 

Strain and elasticity of the separate fibres rather than that of the 
yarn or cloth; but it may be assumed, with considerable show 
of reason, that these figures of Buntrock will represent a fair 
relation between the strength and elasticity of the individual 
fibres. The cause of the lesser increase in tensile strength of 
cotton mercerized under tension as compared with that of the 
same cotton mercerized without tension is to be attributed to the 
fact that when the shrinkage of the fibre is prevented by the 
application of an external force, the cell tissues cannot become 
as compact as otherwise, and there is also an internal strain 
induced which lessens the ultimate strength of the fibre. This 
latter condition also accounts for the lack of any increase in 
the elasticity of the mercerized fibre; the fibre when mercerized 
under tension is already in a stretched or strained condition, and 
can hardly be expected to give the same degree of elasticity as 
if tension had not been applied. 

2. Conditions of Mercerizing. — ^The proper conditions for 
carrying into practical operation the mercerizing process are 
simple and easily reahzed. Caustic soda is the most suitable 
and convenient reagent * for bringing about the hydration of 
the cellulose; and it has been found that a solution of density 
between 60° and 70° Tw. gives the best results. Caustic soda 
solutions of less density than 15° Tw. have scarcely any action on 
cotton; the maximum effect appears to be produced by a con- 
cen ration of about 60° Tw., though the difference between this 
and that obtained at 50° Tw. is not very marked, and even at 
40° Tw. the mercerizing action of the alkali is quite strong. Other 
reagents, however, than caustic alkalies, may be employed for 
the hydrolysis of the cotton. Concentrated mineral acids, such, 
for instance, as sulphuric acid at a density of 100° to 125° Tw., 
will bring about the mercerizing effect more or less perfectly: 
the same is also true of certain metallic salts, most notably the 
chlorides of zinc, calcium, and tin. Beyond a mere theoretical 

* Solutions of caustic potash probably give a somewhat better lustre, and 
the shrinkage of the fibre is less than with caustic soda. But these small ad- 
vantages are not sufficient to compensate for the extra expense which would be 
entailed by the use of caustic potash. 



i62 THE TEXTILE FIBRES. 

and chemical interest, however, mercerizing by means of such 
reagents has no practical value * The addition of various chem- 
icals, however, has been made to the caustic alkali solution with 
beneficial results. It has been observed, for instance, that the 
addition of zinc oxide has a very marked effect, and probably is of 
considerable value in the practical working of the process. The 
addition of glycerin, though perhaps of some benefit in assisting 
in the even and thorough penetration of the liquor into the fibre, 
can hardly be said to appreciably modify the general operation of 
the alkali. t Previous treatment with Turkey-red oil is also of 
benefit for the same reason; this is also true of such substances 
as sodium silicate, sodium aluminate, and soap. 

The temperature at which the reaction is carried out should 
not be higher than the usual atmospheric degree ; in fact, it has 
been recommended to lower the temperature of the caustic soda 
solution by the addition of ice, but this procedure does not appear 
to add anything of material advantage. At elevated temperatures 
caustic soda appears to exert a destructive effect on cotton, prob- 
ably due to the formation of oxycellulose through hydrolysis and 
subsequent oxidation. Beyond a certain temperature the mer- 
cerizing effect rapidly diminishes, and at the boil it is scarcely 
appreciable. J The best results appear to be obtained when the 

* The use of sulphide of sodium or potassium instead of caustic alkali has 
been proposed; but the process yields very uncertain results. It is claimed that 
by adding ether to the caustic soda solution good mercerization can be obtained 
with but httle contraction of the fibre, but as this process requires fifty parts of 
ether to twenty parts of caustic soda solution, the expense renders it ridiculously 
impracticable. It is said that the addition of carbon bisulphide to the bath of 
caustic soda very materially increases the lustre; this causes a disintegration of 
the fibre, however, through the formation of viscose (see p. 153); hence the 
treatment should be very brief, otherwise the cotton will be seriously tendered. 
The mercerized fibre at first is as stiff as horse-hair, but this effect can be removed 
by repeated washing. The sulphur can be removed from the cotton by washing 
in a solution of sal-ammoniac, and this should be done before the material is treated 
with an acid bath, as the latter would cause a precipitation of sulphur on the 
fibre and so spoil the lustre. 

t In the practical manipulation of the mercerizing process it has been found 
that the impregnation with caustic liquor is greatly facilitated by the addition of 
5 per cent, of alcohol on the weight of the caustic soda. 

I Beltzer, however, claims that caustic soda solutions of 65° Tw. gave the 
same results in mercerizing at 90° C. as at 15° C, but the cotton mercerized at 



MERCERIZED COTTON. 163 

temperature is maintained at 20° C, or lower. Above this point 
the contraction of the fibre (which may be taken as a measure of 
the degree of mercerization) grows less and less with rise of tem- 
perature. 

The mercerizing action of caustic soda is rather a rapid one, 
;as it requires only a few minutes for its completion; in fact, it 
appears to take place simultaneously with the impregnation of 
the fibre by the liquid. In ten minutes mercerization is prac- 
tically complete, and lengthening of the time does not increase 
the mercerizing effect; in fact, too long a contact of the cotton 
with the caustic alkali is to be avoided, especially if the impreg- 
nated fibre is exposed to the air, as there is danger of a breaking 
down of the cellular structure and a consequent deterioration in 
the strength of the fibre. The time of immersion also appears 
to be independent of both the temperature and the concentration 
of the alkali. 

There are two ways in which the tension may be applied in 
mercerizing: (a) The material may be held in a state of tension 
during the time of its treatment with the caustic alkali, and until 
the alkali has been washed out, in which case the tension should 
be so maintained that the material cannot shrink; (6) the ten- 
sion may be applied after the material has been treated with the 
caustic alkaH, but before the latter is washed out, in which case 
sufficient tension should be exerted to stretch the material back 
to its original length. If the tension is not applied until after the 
alkali has been removed from the fibre, no lustring effect is pro- 
duced, it is absolutely essential that the stretching should take 
place while the fibre is in the form of an alkali-cellulose, and 
before it has been converted by treatment with water into hydrated 
cellulose. 

According to the experiments of Herbig, the stretching force 
necessary to keep the cotton in its original length during mercer- 
ization is only from a quarter to a third of that necessary to do 

the higher temperature was much more transparent than the other. The lustre, 
however, was in no wise inferior. If the mercerization be conducted at 90° C. 
it is necessary to keep the cotton entirely immersed, to guard it from contact 
with the air, otherwise it will become seriously weakened. 



i64 THE TEXTILE FIBRES. 

the stretching after mercerization ; but there appears to be no 
appreciable difference in the lustre obtained. It would appear, 
however, that stretching beyond a certain point ceases to increase 
the lustre, and to obtain the maximum lustring effect it is not 
necessary to stretch the cotton back to its original length. Her- 
big concluded that stretching during mercerization is disadvan- 
tageous, and it is best to mercerize the yarn loose, wring it, and 
only stretch while rinsing, as the required stretching force is 
then quite small. The best time for stretching, then, is during 
the conversion of the soda-cellulose into the hydrocellulose. If 
the stretching does not take place until after rinsing, almost 
twice the force is necessary to restore the yarn to its original 
length, as when in contact with the lye, and the lustre is decidedly 
inferior. The stretching force also appears to depend on the 
twist, being greater in proportion as the twist is harder.* 

* Herbig gives a summary of his experimental results as follows: 

1. Loose yarn mercerized without any stretching, whether long- or short- 
stapled, and whether with or without a hard twist, has less lustre than unmer- 
cerized yarn. But even with a very slight tension the lustre is greater. 

2. Both with long- and short-stapled cotton the lustre only becomes marked 
when the stretching force is sufficient to bring the yarn back to its original length. 

3. Stretching beyond the original length does not give any increase in lustre. 

4. Considerable difference is observable in the stretching force needed between 
loose mercerization followed by stretching in the lye, and keeping the cotton at 
its original length during mercerization, as in the latter case only one-third to 
one -quarter of the force is necessary to produce the silky lustre. 

5. The stretching of the yarn requires only a small force when mercerized 
loose and if applied when rinsing is actually in progress; for the best time for 
stretching is during the conversion of the soda-cellulose into hydrocellulose. 

6. When rinsing is over, twice as much force is needed to restore the original 
length as is required for yarn still in contact with the lye; and yarns so treated 
contract somewhat on drying, and exhibit an inferior lustre. 

7. The stretching force necessary in mercerizing yarn varies with the twist, 
and in general is greater in proportion as the twist is harder. 

8. The production of the silky lustre does not depend primarily on the amount 
of force employed in stretching, as soft yarn with only a small amount of twist 
can be lustred. 

9. The production of the silky lustre is independent of the cotton being long- 
er short-stapled, as short-stapled American cotton with even a loose twist can 
be given a silky lustre. 

10. The production of a high degree of lustre depends to a considerable extent 
. on the fineness of the fibre, and its natural lustre. This is apparent in mercerizing 

sea island and Egyptian cotton. 



MERCERIZED COTTON. 165 

By the washing of the material after steeping in caustic alkah, 
a twofold object is gained. In the first place, the action of the 
water on the alkali-cellulose is to effect a chemical transforma- 
tion into cellulose hydrate, and this action is as really essential 
to mercerizing as the action of the caustic soda itself. In the 
second place, the washing is conducted for the purpose of remov- 
ing all excess of caustic alkali from the material.* Caustic soda 
is held quite tenaciously by cotton, and it requires a very thorough 
and long-continued washing to remove the last traces of this 
compound. In order to shorten the period required for washing, 
it is customary to give the cotton first a rinsing in fresh water, 
after which the tension may be relieved, and then to wash with 
acidulated water, using acetic acid for this purpose. f On dry- 
ing the material without further washing, it will be found that 
the acetic acid has imparted to the cotton a certain degree of 
' ' scroop ' ' somewhat after the nature of silk, without in any man- 
ner tendering the fibre. If other acids, and especially mineral 
acids, are employed for washing, a subsequent rinsing with fresh 
water and soaping is necessary for the purpose of neutralizing 
all of the acid, which would otherwise seriously tender the goods 
on drying unless the amount of acid employed is so accurately 
adjusted as not to leave any free acid in the fibre. 

The character of the fibre employed has a considerable influ- 
ence on the success of the mercerizing process. From the very 
nature of the fact that a considerable degree of tension must be 
appHed to the fibre during the process in order to obtain the 
desired lustre, it would be natural to expect that the longer the 
staple of the fibre the more readily would it lend itself to the 
requirements of the operation. And such, indeed, is found to 
be the case; the long-stapled sea-island % and Egyptian varieties 

* When mercerized cotton is rinsed with ammonia instead of water it retains 
its gelatinous, parchment-like consistency throughout the rinsing, and can be 
s'tretched to its original length without breaking. If the cotton is then rinsed with 
water while still stretched, the fibre regains its original appearance, and acquires 
a lustre as good as that obtained in the usual way. 

•}■ Sulphuric acid is much used in the washing. The acid employed is of 1° B. 
strength, and at a temperature of 50° C. 

\ The preparation by combing of cotton for mercerization has a considerable 



1 66 THE TEXTILE FIBRES. 

of cotton are those especially adapted for use in the preparation 
of mercerized cotton, while the shorter-stapled varieties are but 
little employed for this purpose, as the lustre obtained with them 
is by no means as pronounced.* The quality of being mercerized, 
however, is not an inherent property of any special variety of 
cotton, as was formerly supposed to be the case; any variety of 
cotton is capable of mercerization, the only essential being that 
the fibre shall be maintained in a state of tension. In order that 
this condition be realized with short-stapled fibres, the yarn 
operated upon must be tightly twisted in order to present suffi- 
cient cohesion among the individual fibres to allow of the high 
tension required; this, on the other hand, prevents an even and 
thorough penetration of the caustic alkali into the substance of 
the fibre, so that, on the whole, the results obtained with short- 
stapled fibres are not at all comparable with the long- stapled 
varieties.! By later improvements in the manner of applying 

influence on the subsequent lustre of the yarn. Sea-island cotton possesses a 
rather silky fibre to begin with, and this is made more adaptable to the production 
of a high lustre by combing, in which operation the fibres are arranged parallel, 
and still further by gassing, which burns off the minute outer hairs. Yarns possess- 
ing considerable lustre were made in this manner with fine counts of sea-island 
cotton long before the discovery of lustring by mercerization, and it was always 
recognized that the parallelism of the fibres so obtained by combing (and some- 
times a second combing) was a great factor in the production of a silky and 
lustrous yarn. 

* Fabrics of vegetable fibres (cotton or linen) may also be mercerized in 
patterns by printing on certain compounds capable of resisting the action of the 
caustic soda in the subsequent mercerizing process. Resists suitable for this 
purpose are, in the first place, organic compounds which readily coagulate, such 
as albumin and casein; and secondly, such salts, acids, or oxides which may 
act by neutralizing the caustic alkali, or from which a hydrate may be precipi- 
tated on the fabric by its action. Such compounds, for instance, as the salts of 
aluminium or. zinc, organic acids, and the oxides of zinc, aluminium, or chromium 
are quite suitable. Very beautiful effects are said to be obtainable by this 
process. 

t Boucart gives the following reasons why only long-stapled cotton, and that 
only in particular counts, gives good results on mercerization. A simple thread 
consists of a sort of twisted wick composed of nearly parallel fibres. The twist 
depends, as regards the angles it makes with the length of the thread, both upon 
the kind of cotton and upon the count of the yarn. Of the two sorts of simple 
yarns, warp-yarns have more cohesion among their elements than tensile strength, 
while the reverse is the case with weft-yarns. The result is that under gradually 



MERCERIZED COTTON. 167 

the tension, however, it would seem that, by realizing the proper 
mechanical conditions, even cotton of comparatively short staple 
will be capable of being mercerized in a more successful man- 
ner than heretofore.* 

3. Properties of Mercerized Cotton. — Outside of its high 
lustre and somewhat increased tensile strength, mercerized cotton 
exhibits but few apparent differences from the ordinary fibre. 
Towards dyestuffs and mordants it is rather more reactive, and 

increasing tension weft-fibres slide past one another without breaking, but warp- 
fibres break before any such occurrence takes place. The degree of twist also 
depends on the mean staple, and the angle between the thread and the axis at 
any point is proportional to the length of the thread. The degree of twist which 
is required to make the cohesion exceed the tensile strength depends naturally 
on the strength of the fibre. The mercerizing process tends to shorten each 
individual fibre, and this shortening is resisted by tension in the direction parallel 
to the a.xis of the thread. Hence the greater the angle the thread makes with 
that axis the less is the effect of the tension, and if any portion of the fibre is at 
right angles to the axis it is not affected by the tension at all. Hence a simple warp 
thread can only receive a medium amount of gloss from mercerization, and the 
less the greater the twist. Slightly twisted threads must give the best lustre, but 
if the cohesion of the fibres is less than the contractile force exerted by the lye, 
the fibres slip past each other and no lustre is produced. But if the weft-threads 
are fixed, as in piece goods, they take a better lustre than the warp, although the 
latter is usually made of better cotton. Short-stapled cotton lustres badly because 
it must be more tightly twisted. The best lustre of all is obtained with twofold 
twist, in which the outer fibres lie parallel to the axis, and the yarn should be 
well singed to remove projecting threads. 

* The process of mercerizing has been subject of late to a great number of 
patents, especially by Thomas and Prevost of Germany. This has resulted in 
considerable litigation in many countries. As far as the actual chemical process 
itself is concerned, however, there does not appear to have been any material 
advance beyond the facts first discovered by Mercer and patented by him in 1850; 
with regard to the element of carrying out the process under tension, it may be 
said that this was first described and patented by Arthur Lowe in 1890, and this 
included the application of tension either during or after the treatment with caustic 
alkali. Lowe's object in stretching the material, however, was primarily to pre- 
vent the loss encountered by the shrinkage of the goods, though he does also make 
a specific statement that the cotton acquires an increased lustre and finish by 
the process. The only novelty put forward by Thomas and Prevost was the use 
of a particular kind of cotton, that is, long-stapled varieties ; but as both Mercer's 
and Lowe's patents claim the use of all varieties of cotton, it is difficult to see 
on what ground Thomas and Prevost can substantiate their claim for a patent. 
Patents covering the process of mercerizing appear to be without foundation; 
though for machinery and appliances for carrj-ing out the same such patents 
may be perfectly legitimate. 



1 68 THE TEXTILE FIBRES. 

consequently will dye deeper shades with the same amount of 
dyestuff than ordinary cotton ; this property is rather to be ascribed 
to the increased absorptivity of the fibre than as the result of any 
chemical modification of the cellulose composing it; it is also 
independent of the method of mercerizing, that is, whether accom- 
panied by tension or not. 

Microscopically the mercerized cotton fibre exhibits a con- 
siderable difference from that of ordinary cotton. Whereas the 
latter when viewed under the microscope appears as a twisted 
flat band with thickened edges, and in cross-section like a col- 
lapsed tube, mercerized cotton appears as a smooth rounded 
cylindrical fibre, the cross-section of which is more or less cir- 
cular. It rarely happens that a fibre absolutely loses all of its 
twist, though the degree of mercerization may be measured by 
the freedom of the fibre from irregularities and twists. Under 
ordinary conditions when the cotton is mercerized in a state of 
tension, it will also be found that many fibres will remain in 
their original form, or unmercerized, whereas others will be 
mercerized only in portions of their length. The microscopical 
examination of mercerized cotton is important in determining 
just how perfectly the process has been carried out, which may be 
judged by the relative number of unmercerized or partially mer- 
cerized fibres which may be present. 

Cotton may be mercerized either in the form of yarn or of 
cloth, and it is principally done in the unbleached condition. 
There has been some dispute as to which is best : to mercerize first 
and bleach, or to bleach first and then mercerize; experience, 
however, appears to favor the first method. In the bleaching 
operations, which usually involve a rather severe treatment of the 
cotton first with moderately strong alkalies and subsequently 
with solutions of bleaching powder, the fibre suffers more or less 
chemical alteration so that in the mercerizing process it can no 
longer enter into chemical union with the caustic soda employed; 
and hence true mercerization is not effected. Although cotton 
should be thoroughly scoured ("boiled out") before being mer- 
cerized, it is best not to use alkahes for the purpose, but to employ 
Turkey- red oil (or other suitable sulphated oil) or soap. If 



MERCERIZED COTTON. 169 

bleaching is carefully conducted after mercerizing, the injury to 
the lustre of the fibre is very slight. Mercerized cotton does not 
require a prolonged boiling in alkalies previous to the operation 
of bleaching as with ordinary cotton. To obtain the best condi- 
tions for high lustre yarn should be well "gassed" (singed) before 
mercerizing, as otherwise the external, hairy fibres remain loose 
and cannot be subjected to tension. As a result these fibres 
shrink, and, remaining without lustre themselves, hide to a cer- 
tain extent the lustred surface of the yarn. Moreover, caustic 
soda has a felting action on these free filaments, and felting is 
especially harmful to lustre. 

In mercerizing cloth the action taking place between the 
sizing materials (always present to a greater or lesser degree in 
cotton cloth) and the caustic alkali is sufficient at times to raise 
the temperature considerably, which may result in a deficient 
lustre. In such cases recourse must be had to artificial cooling 
by addition of ice or a current of cold water in order to prevent 
an undue rise in temperature. 

When mercerized cotton is to be bleached, it is best, after the 
first rinsing, to remove the major portion of the caustic soda and 
arrest the mercerization, not to rinse again in acidulated water, as 
would ordinarily be done if the material were not to be immedi- 
ately bleached. The small amount of caustic soda which still 
remains in the cOtton acts in a beneficial manner in bleaching. 

A silky lustre resembling that produced by mercerization can 
be given to cotton cloth by means of what is known as a calender 
finish. This is accomplished by passing the cloth between rollers 
under heavy pressure, one of the rollers being engraved with 
obliquely set lines ruled from 125 to 600 to the inch. The effect 
is to produce a large number of parallel, flat surfaces on the cloth, 
which causes it to acquire a high lustre. By conducting the oper- 
ation with hot rollers quite a permanent finish can be produced 
which closely approximates mercerized cotton. Cloth so fin- 
ished, however, loses its lustre in a large degree on washing. 
The method is chiefly known as the " Schreiner process." 



CHAPTER XIII. 

ARTIFICIAL SILKS; LUSTRA-CELLULOSE. 

Owing to the high price and value of silk as a textile fibre, 
there have been numerous attempts made to produce an artificial 
filament resembling it in properties. Several of these processes 
have been attended with a considerable degree of success, and 
at the present time artificial silk has become a commercial article, 
and is used in considerable quantity by the textile trade. The 
varieties of these silks divide themselves into the following classes : 

(i) Pyroxylin silks, made from a solution of guncotton in a 
mixture of alcohol and ether. 

(2) Fibres made from a solution of cellulose in ammoniacal 
copper oxide or chloride of zinc. 

(3) Viscose silk, made from a solution of cellulose thiocarbon- 
ate. 

(4) Gelatin silk, made from filaments of gelatin rendered 
insoluble by treatment with formaldehyde. 

With the exception of the last class, all of these so-called silks 
are filaments of cellulose, resolidified from various forms of solu- 
tions, hence it has been proposed to give these fibres the general 
name of lustra-cellulose, as one more descriptive of their true 
nature. 

The large majority of the lustra- cellulose used in trade at the 
present time falls under the first class of pyroxylin silks. This 
represents the oldest and most successful method employed for 
the manufacture of this interesting fibre; and there are three 
chief processes by which the silk is made, known by the names 
of the respective inventors: Chardonnet, du Vivier, and Lehner. 
All of these processes use a solution of nitrocellulose as a base, 

170 



I 



/1RTIFICML SILKS; LUSTRA-CELLULOSE. 171 

and employ the same general mechanical idea to produce the 
filament or fibre, the principle being to force a solution of 
nitrocellulose through a fine capillary tube, coagulate the thin 
stream of solution thus obtained, and finally denitrate and reel 
the thread or filament so obtained. As described on p. 150, 
cellulose, on treatment with nitric acid, can be made to yield a 
series of nitrocelluloses, the exact compound obtained being 
dependent upon the conditions of treatment. 

Chardonnet silk is prepared from octonitrocellulose, dissolved 
in a mixture of alcohol and ether. The solution is coagulated 
by passage through water, and is subsequently denitrated * 
by a treatment with dilute nitric acid, chloride of iron, and am- 
monium phosphate. It forms a glossy, flexible fibre, possessing 
the peculiar "feel" and "scroop" of true silk. 

The basis of du Vivier's silk is a solution of trinitrocellulose 
in glacial acetic acid. In practice, this is mixed with a solution of 
gutta-percha in carbon disulphide, and one of isinglass in glacial 
acetic acid. Small quantities of glycerin and castor-oil are 
added, and the mixture is drawn through the spinning-tubes into 
water, where it becomes coagulated. The thread which is so 
formed is treated successively with soda, albumin, mercuric 
chloride, and carbon dioxide. Du Vivier's silk is hard, and very 
white and glossy. 

Lehner employs a solution of nitrocellulose in ether and 
methyl alcohol, to which he adds a solution of natural silk in 
glacial acetic acid. The thread is coagulated by passage through 
a mixture of turpentine, chloroform, and juniper-oil, and is after- 
wards treated with a solution of sodium acetate, f 

* When first prepared, pyroxylin silks were very inflammable, which led to 
their being regarded with disfavor. The processes of denitration, however, have 
now rendered them even less inflammable than ordinary cotton. Antiphlogin is the 
trade-name of a mixture for the purpose of overcoming the inflammable nature 
of artificial silk. It consists of boric acid, phosphate of ammonia, and acetic 
acid. Pyroxylin steeped in this solution is said to be incombustible. 

f The manufacture of artificial silk has of late years become an enterprise 
of commercial importance. There are factories producing pyroxylin silk 
at Besang-on (France), Spreitenbach and Zurich (Switzerland), Wobton (Eng- 
land), and Elberfeld (Germany). The fibres are formed by forcing the ether- 
alcohol solution of pyroxyhn through glass capillary tubes and winding them on 



172 THE TEXTILE FIBRES. 

The chief drawback to the rapid progress of collodion silk is 
its behavior with water.* When wetted the fibre loses its orig- 
inal strength to such a degree that it must be handled with great 
care. Soap solutions and free dilute acids have no injurious 
effect, but free alkaHes rapidly disintegrate the fibre and finally 
dissolve it completely. The material is difficult to dye on account 
of the weakening action of water, and the operation must be 
carried out with great care. The dyeing is accomplished with- 
out the addition of either soap or acid to the bath. The basic 
coloring-matters and some of the direct cotton colors appear to 
be the best dyestuffs to employ. 

Besides the three processes already given of obtaining collo- 
dion silk, there are other methods for the manufacture of this 
artificial product. Langhaus employs as a raw material a prep- 
aration from cellulose and sulphuric acid. Cadarat uses nitro- 
cellulose, dissolving it in a very complex mixture of glacial 
acetic acid, ether, acetone, alcohol, toluol, camphor, and castor-oil. 
This forms a plastic mass which is treated with some proteid 
substance, such as gelatin or albumin dissolved in glacial acetic 
acid. After spinning, the fibres are treated with tannin in order 
to render them elastic. 

Hoepfner f has prepared porous acid-proof fabrics to be 
employed for filtering purposes in electrolytic work by using cot- 
ton yarn which has been nitrated. The latter can be woven 
along with asbestos, glass, or other mineral fibres in the making 
of the fabric. 

frames. As the solution is very viscous, it requires a pressure of 45 atmospheres 
to discharge it through the capillary openings. It viras formerly the custom to 
carry out the dyeing of pyroxylin silk in the pulp, but this proved to be imprac- 
ticable, and at present it is chiefly dyed in the form of yarn. The proportion 
between the price of natural and artificial silk is approximately as follows: Natu- 
ral silk, $10 per kilo; pyroxylin silk, $4.75 per kilo; gelatin silk (vanduara), $2.40 
per kilo. 

* Artificial silk appears incapable of withstanding high temperatures, being 
rapidly charred and destroyed when heated to 150° C. A method for the analysis 
of materials containing this substance has been proposed, using this fact as a basis. 
The material under examination is heated for ten minutes at 200° C. Cotton, 
wool, and silk are not materially injured, but artificial silk is completely carbon- 
ized, and on rubbing will be reduced to a dust. 

t Fdrher Zeit., 1897, No. 5. 



I 



ARTIFICIAL SILKS; LUSTRA-CELLULOSE. 173 

If nitrated cotton be examined under the microscope, a con- 
siderable alteration in its appearance will be observed. The 
fibres are much thicker in the wall, and are consequently stiff er 
than those of ordinary cotton. The lumen has either vanished 
entirely or become very much contracted, and this appears to be 
due to the swelling of the cell- walls. In->the walls of the fibre 
there will also be noticed numerous fractures or cracks which often 
assume a spiral shape. The nitration has evidently rendered the 
fibre much more brittle and has decreased its elasticity. 

Solutions of nitrocellulose have been employed for a number of 
purposes, such as the production of films for photographic use, 
the manufacture of lacquers, etc. The author has also success- 
fully utilized such a preparation for the waterproofing of paper 
and other materials. It also forms an excellent waterproof sizing 
and stiffening agent for all manner of textile fabrics and hats. 

As the solutions of nitrocellulose possess great viscosity, it is 
difficult to prepare a very concentrated solution. The addition of 
formaldehyde or benzol, however, to the ordinary solvents, will 
increase the dissolving capacity considerably, and also give a 
more mobile solution. Epichlor- and dichlorhydrins also act as 
excellent solvents for nitrocellulose, being capable of dissolving 
it in any proportion. 

Vanduara silk * is a thread of gelatin, and consequently differs 
from the other artificial silks in that it consists of animal tissue 
and not vegetable. Due to this circumstance it has more analogy 
chemically to true silk than the various cellulose silks. The 
manufacture of vanduara silk is conducted by pressing an aqueous 
solution of gelatin through a fine capillary tube; the thread so 
produced is carried on an endless band through a drying- cham- 
ber. The soft gelatin thread, of course, flattens out considerably 
during this operation, hence the silk eventually forms a flat, rib- 
bon-like fibre. After drying and properly reeling, the fibre is 
treated with vapor of formaldehyde, which causes the gelatin to 
become insoluble in water. By varying the pressure on the 

* Vanduara silk is an English invention, the patentee being Adam Millar. 
The silk has never appeared on the market as a commercial commodity, and 
the process does not seem to have met with any marked degree of success. 



174 THE TEXTILE FIBRES. 

gelatin solution, whereby it is forced through the capillary tube, 
the thickness of the fibre may be increased or diminished. The 
same result may be attained by varying the speed of the endless 
band which carries the thread after coming from the capillary 
tube. The silk may be dyed either in the ordinary way in skein 
form after reeling, or the gelatin solution may be colored before 
the thread is drawn out. The fibre is very lustrous, and if the 
filaments are drawn fine enough, the silk is soft and pliable. 

Hassac * gives a comparison of several makes of artificial 
silk. Chardonnet's and Lehner's silks are very similar in appear- 
ance; they are more lustrous than real silk, but are stiff er, and 
do not possess the characteristic feel. Cellulose silk made by 
Pauly's ammoniacal copper oxide process is similar to the former 
in appearance, but its lustre is even better, and it has the charac- 
teristic feel of true silk. Lehner's silk under the microscope is 
characterized by deep longitudinal grooves and small air-bubbles ; 
its cross-section is highly irregular. Pauly's silk shows fine 
longitudinal grooves, and minute transverse lines in the centre 
of the fibres; its cross-section is regular, approaching a circle or 
ellipse. Hammel's gelatin silk is almost circular in outline, 
and is free from grooves and bubbles; in polarized light it is 
singly refracting, while the others are doubly so. 

As the collodion silks always contain some nitro-compound, 
they, give a blue color with diphenylamin and sulphuric acid. 
Water causes all the artificial silks to swell, while alcohol or 
glycerin contracts them. In strong sulphuric acid the collodion 
silks swell rapidly and dissolve; Pauly's cellulose silk gradually 
becomes thinner and dissolves; gelatin silk only dissolves on 
strong heating. Chromic acid dissolves all artificial silks in the 
cold; real silk dissolves but slowly; while cotton and other vege- 
table fibres are unaffected. Caustic potash does not dissolve 
the collodion or cellulose silks, but both the gelatin silk and 
real silk are soluble on boiling. Schweitzer's reagent dissolves 
collodion and cellulose silks ; whereas gelatin silk is insoluble, but 
stains the liquid a bright violet. Alkaline copper glycerin solu- 
tion at 80° C. dissolves real silk immediately. Tussah and gelatin 

* Chem. ZeiL, 1900, 235, 267, 297. 



ARTIFICML SILKS; LUSTRA-CBLLULOSE. 



175 



silks dissolve when boiled for one minute; the other silks are not 
affected. lodin solution colors artificial silks an intense red, 
which changes to a transient pale blue on washing with water in 
the case of collodion silks, though cellulose silk does not show 
this blue. lodin and sulphuric acid stain true silk yellow, 
gelatin silk brown, collodion and cellulose silks blue. 



Silk. 



Moisture. 



Air- 
dry, 
Per Ct. 



Sp. Gr. 



Satu- 
rated, 
Per Ct. 



Fibres to 


Tens. Strength, 


Sq. Mm. 


Kilo, per 




Sq. Mm. 


Wet. 


Dry. 


Wet. 


Dry. 


9710 


9710 


37-0 


37-0 


640 


II35 


2.2 


12.0 


683 


1620 


I.O 


22.3 


413 


1 180 


1-5 


16.9 


742 


1550 


3-2 


19. 1 


265 


945 


0.0 


6.6 



Exten- 
sion, 
Per Ct. 



Real silk 

Chardonnet 

" (Walston). 

Lehner 

Pauly 

Gelatin 



S.71 
II . II 
11.32 

10.45 

9.20 

13.98 



II 1.36 



1-52 
1-53 
I-5I 
1.50 

1-37 



21 .6 
8.0 
7.9 
7-5 

12.5 
3-& 



Strehlenert and Westergren give the following figures for the 

tensile strengths of various natural and artificial silks. The 

figures indicate the breaking strains in kilograms per square 
millimeter section: 

Natural Silks. 

Dry. Wet. 

Chinese silk 53-2 46. 7 

French raw silk 50.4 40 . 9 

French silk, boiled-off 25.5 13-6 

" " dyed red and weighted 20.0 15-6 

" " blue-black, weighted 110% 12. i 8.0 

" " black, weighted 140% 7.9 6.3 

" " black, weighted 500% 2.2 

Artificial Silks. 

Chardonnet's collodion, undyed 14 • 7 1.7 

Lehner's collodion, undyed 17. i 4.^ 

Strehlenert's collodion, undyed 15. 9 3.6 

Pauly's cuprammonium, undyed 19. i 3.2 

Viscose silk, early samples 11. 4 3.5 

" " latest samples 21.5 

Cotton yarn (for comparison) 11 . 5 18 . 6 

Cotton may be "animalized" — that is, given the dyeing 
properties possessed by animal fibres — in a variety of ways. 



176 THE TEXTILE FIBRES. 

The material may be impregnated with albumin and afterwards 
steamed; this method is employed to some extent in printing, 
being used chiefly in connection with the direct cotton colors, to 
prevent their bleeding. A solution of casein may also be used 
instead of albumin, with similar results. The same property 
may also be imparted to cotton by treatment with tannic acid 
and gelatin or lanuginic acid, but with doubtful results; though 
Knecht describes a method which is said to give satisfaction, the 
cotton being impregnated with a solution of lanuginic acid and 
allowed to dry in the presence of formaldehyde, when the fibre 
becomes coated with an insoluble film possessing a remarkable 
affinity for the substantive dyes. Vignon claims that by treating 
cotton under pressure with ammonia in presence of zinc chloride 
or calcium chloride, the fibre acquires an increased affinity for 
the basic and acid dyestuffs. His results, however, have not 
been confirmed. 

A silk-like appearance may also be given to vegetable fibres 
by treatment with a solution of silk (fibroin) in some suitable 
solvent, such as hydrochloric, phosphoric, sulphuric acids, or 
cuprammonium, etc. The silk employed is made up of scraps 
and waste which would otherwise be useless. Better results are 
obtained if the cotton material be treated with a metallic or tannic 
acid mordant before immersion in the silk solution, and should 
afterwards be calendered and poHshed in order to obtain a glossy 
appearance. 

Viscose silk, from solutions of cellulose thiocarbonate, has 
been made with some degree of commercial success in the 
United States. It is principally made in coarse numbers, and is 
used as an artificial horse-hair. Finer numbers of considerable 
softness have also been made, for use in braids, passementerie, 
etc. 



CHAPTER XIV. 

LINEN. 

I. Preparation. — Linen is the fibre obtained from the flax 
plant, botanically known as Linum nsitalissimum.'^ The fibre is 
prepared from the bast of the plant by a process called retting, 
which has for its purpose the separation of the fibrous cellulose 
from the woody tissue and other plant membranes. Historically, 
linen appears to have been the earliest vegetable fibre employed in- 
dustrially, having been used at a much earlier date than cotton. 
Though grown more or less in every country, at present the 
cultivation of flax is principally carried on in France, Ireland, 
Belgium, Holland, Russia, America, and Canada. The bast 
tissue, which is used for the fibre, is situated between the bark 
and the underlying woody tissue. 

The flax plant, after attaining its proper growth, is either cut 
down or pulled up by its roots, and subjected to a process tech- 
nically known as rippling, the plants being drawn through a 
machine which removes the seeds and leaves. "f The remaining 

* Botanists recognize upwards of one hundred species of the flax plant, but, 
of all these, the only one possessing industrial importance and the only one 
readily cultivated is the Linum usitatissimum (or L. commun), which has a blue 
flower. The North American Indians have long used the fibre of L. luvisii, 
which differs from the ordinary cultivated flax in having three stems growing 
from a perennial root. The most ancient species of flax brought under cultiva- 
tion is thought to be L. angustijolium; the Swiss lake-dwellers are said to have 
grown it, as also the ancient inhabitants of northern Italy. The flax culti- 
vated in the eastern countries, in Assyria, and Egypt appears to have been the 
common variety L. usitatissimum. 

t Besides being cultivated for its fibre, the flax plant is also grown for its seed, 
which yields the valuable oil known as linseed. It possesses good drying qualities, 

177 



178 THE TEXTILE FIBRES. 

Stalks are then tied in bundles and placed in stagnant water, 
where they are allowed to remain for a number of days. Active 
fermentation soon starts, resulting in the decomposition of the 
woody tissues enclosing the cellulose fibres. When the process 
has gone sufficiently far, the bundles of fermented stalks are 
removed and passed through a number of mechanical operations, 
whereby the decomposed tissues are removed and the linen fibres 
are isolated in a purified condition. This method of retting 
with stagnant water is known as "pool- retting." As the fer- 
mentation causes the evolution of considerable gas, in order to 
keep the bundles of stalks submerged they are loaded with stones 
or boards. The time of steeping in the water varies with cir- 
cumstances from five to ten days. Another method of retting 
is to steep in running water. The famous Courtrai flax of Bel- 
gium is retted in this manner in the river Lys. The flax-straw, 
after pulling, is placed in crates and submerged in the water of 
this stream for a period of four to fifteen days, depending on the 
temperature and other influences. Courtrai flax is of a creamy 
color, whereas pool-retted flax is a rather dark bluish brown 
color. The excellent, quahties of the Courtrai flax are said to be 
due to the action of the soft, slowly running, almost sluggish 
waters of the river Lys, and to the pecuHar ferment existing 
therein. Another method employed for obtaining the fibre from 
flax is known as dew-retting, as the flax-straw is spread out in a 
field and exposed for a couple of weeks to the action of the dew 
and the sun. Dew-retting, however, gives the most uneven and 
least valuable product of the three methods employed, and the 
fibre is rather dark in color. There have also been several chemi- 
cal methods proposed for retting flax, such as heating with water 
under pressure, boiling with solutions of oxalic acid, soda-ash, 
caustic soda, etc. None of these, however, have proved of any 
industrial value, and the old natural methods are still adhered 

and hence is extensively used for the preparation of paints and varnishes. The 
best seed-flax is grown in tropical and subtropical countries, whereas the best 
fibre-flax is grown in more northern climates. The seed obtained from the latter 
variety, though utilized as a by-product, produces only an inferior grade of, oil. 
The oil-cake left after expressing the oil from the seed is an excellent cattle-food 
and is largely used for this purpose. 



LINEN. 1 7 9 

to. Additions of various chemicals to the retting waters have at 
times proved of value, hydrochloric or sulphuric acid sometimes 
being used to advantage.* 

The intercellular substance holding the flax fibres together 
consists mostly of calcium pectate, and the real object of retting 
is to render this substance soluble so that it may be removed by 
the after-processes of treatment. Winogradsky has succeeded in 
isolating the particular organism that is the active agent in the 
pectin fermentation. It is an anaerobic bacillus which readily 
ferments pectin matters, but has no action on cellulose. By 
adding salts promoting the growth of the baciUus to the water 
employed in retting, it has been found possible to reduce the 
time of retting very considerably. It has been claimed that 
fatty acids exert a solvent action on the resinous and pectin mat- 
ters present in vegetable fibres, and a method for the decortication 
of flax and other bast fibres has been devised as follows: The 
raw fibres are impregnated with boiling soap solutions, after 
which ammonium chloride is added, which liberates the fatty 
acids. After several hours' treatment these dissolve all gummy 
and resinous matters; the fibres are then treated with weak 
caustic alkali, after which they are washed and dried, when they 
should be thoroughly disintegrated. Ramie may be treated with 
borated water. Good results are said to be obtained by this 
method. 

The flax stalks, after rippling and being deprived of their 
leaves and seeds, are known as flax-straw. The latter in the air- 
dry condition contains from 73 to 80 per cent, of wood, marrow, and 
bark, and 20 to 27 per cent, of bast. The general structure of flax- 
straw, and of bast stalks in general, is shown in the schematic 
drawing (Fig. 38). 

The Hnen fibre as it is obtained from the plant and as it appears 
in trade is in the form of filaments the length of which varies 

* Schenk's method of retting is to steep in warm water, a constant temperature 
of 35° C. being maintained. It is said that the fermentation may be completed 
by this method in fifty to sixty hours, and gives a larger yield and a better product 
than the natural processes of retting. In steam-retting, the bundles of flax-straw 
are placed in iron cylinders and heated with live steam or hot water under pressure; 
but the process does not appear to be successful. 



i8o 



THE TEXTILE FIBRES. 



considerably with the manner and care employed in decorticating, 
and may be from a few inches to several feet. These filaments 
are composed structurally of small elements or cells. Wiesner 
gives the following dimensions of several varieties of flax fila- 
ments : 



Kind of Flax. 


Mean Length 

of the Purified 

Flax Fibre. 

mm. 


Mean Breadth, 
mm. 




060 

410 
280 

» 


0-255 
0. 114 
0.105 
0.202 
O.II9 




Belgian Courtrai 

Austrian 

Prussian 





2. Chemical and Physical Properties. — ^The flax fibre appears 
to consist of pure cellulose * and shows no signs at all of being 
lignified. It is strongly swollen by treatment with Schweitzer's 
reagent, but, unlike cotton, it does not completely dissolve therein, f 

The color of the best varieties of flax is a pale yellowish white. 
Flax retted by means of stagnant water, or by dew, is a steel-gray; 
and Egyptian flax is a pearl-gray. The pale-yellow color of flax 
is due to natural pigment, but the other color arises from the 
decomposition of the intercellular matter, which is left as a stain 
on the fibre. Flax that has been imperfectly retted shows a 



* In order to isolate pure flax cellulose, Cross and Bevan have recommended 
the following procedure: The non-cellulosic constituents of flax are pectic com- 
pounds which are soluble in boiling alkaline solutions. The proportion of such 
constituents varies from 14 to t,;^ per cent, in different varieties of flax. T'hey may 
be completely extracted by first boiling the fibre in a dilute solution of caustic 
soda (i to 2 per cent.) ; the residue will consist of flax cellulose, with small remnants 
of woody and cuticular tissue, together with some of the oils and waxes associated 
with the latter. By treatment with a weak solution of chloride of lime, the woody 
tissue is decomposed, and is then removed by again boiUng in dilute alkali. The 
remaining cellulose is then further purified from residual fatty and waxy matters 
by boiling with alcohol and finally with ether-alcohol mixture. Flax cellulose 
prepared in this manner appears to be chemically indistinguishable from cotton 
cellulose . 

t In swelling, the fibre blisters considerably, but not in as regular a manner as 
cotton. The inner layers of the cell withstand the action of the reagent the longest 
and remain floating in the liquid, like the cuticle of cotton. Parenchym and 
intercellular matter adhering to the fibre also remain undissolved in the reagent. 



LINEN. 



i8r 



greenish color. The natural color of Hnen is readily bleached 
by solutions of chloride of Hme in a manner similar to the bleach- 
ing of cotton. But the Unen fibre suffers considerable deteriora- 
tion thereby. There are four grades of linen-bleaching — quar- 
ter, half, three-quarters, and full bleach. The whiter the fibre 
is bleached, the weaker it becomes. The lustre of linen is quite 
pronounced and almost silky in appearance; flax that is over- 
retted is dull in appearance. Egyptian flax is also dufl, due to 
the cells being coated with residual intercellular matter. 

The flax fibre is much stronger than that of cotton, though 
overretted flax is brittle and weak. 

The bast-cells of the flax fibre may be isolated by treatment 
with a dilute chromic acid solution. They are cylindrical in 




A B 

Fig. 370. — Micrograph of Flax Fibre. 
A, longitudinal view, showing jointed structure and tracing of lumen; B, cross- 
sections. 

form and taper to a point at each end. At the middle they 
measure 12 to 26 //, with an average of about 15 //.* The 
length varies from 4 to 66 mm., with an average of about 
25 mm. The ratio of the length of the fibre to its breadth is 
about 1200. Under the microscope the surface of the fibre 
appears smooth or marked longitudinally, with frequent trans- 



* According to Vetillard, 15-37 A^ ^th an average of 22 pu 



l82 THE TEXTILE FIBRES. 

verse fissure lines and jointed structures. On treatment with 
chloriodide of zinc the latter are colored much darker than the 
rest of the fibre and are thus rendered more apparent. The 
lumen appears in the centre of the fibre as a narrow yellow line, 
and it is usually completely filled with protoplasm. In cross- 
section the fibres of flax are polygonal, with rounded edges, show 
a large lumen, and a relatively thin cell-wall. In these respects 
they are very similar to hemp, but may be distinguished from the 
latter, however, in that they do not aggregate in thick bundles, 
but are more or less isolated from each other, so that the cross- 
section frequently shows but one fibre, and seldom more than 
three or four* (see Fig. 37^1). 

The following analyses show the composition of two typical 
specimens of flax (H. Miiller) : 

I. II. 

Per Cent. Per Cent. 

Water (hygroscopic) 8. 65 10. 70 

Aqueous extract 3-65 6. 02 

Fat and wax 2 . 39 2.37 

Cellulose 82.57 7i-5o 

Ash (mineral matter) o. 70 i . 32 

Intercellular matter 2.74 9 • 41 

Highly purified flax appears to approximate very closely to 
the composition of cotton. The ordinary flax fibre of trade may 
be said to contain about 5 per cent, less of cellulose than cotton, 
there being about that much more impurity present in the form 
of intercellular matter and pectin bodies.f The hygroscopic 

* Other differences from hemp exhibited by the linen fibre are : (a) the cross- 
section does not show an external yellow layer of lignin when treated with iodin 
and sulphuric acid; (h) it gives reactions for pure cellulose only, that is, iodin and 
sulphuric acid color the fibre a pure blue, and anilin sulphate gives no color, 
though at times there are shreds of parenchym tissue present which are colored 
yellow by this latter reagent and appear to be lignified; (c) the lumen of the hemp 
fibre is seldom filled with yellowish protoplasm like that of the linen fibre; {d) the 
linen fibres end in sharp points, whereas those of hemp do not. 

t The flax fibre contains a certain wax-like substance, varying in amount 
from 0.5 to 2 per cent. It may be extracted from the fibre by means of benzene 
or ether. The color of the wax obtained varies with that of the flax from which 
it is obtained. It has a rather unpleasant odor, resembling flax itself. Its melting- 
point is 61.5° C, and its specific gravity at 60° F. is 0.9083. According to Hof- 
meister this wax consists of 81.32 per cent, of unsaponifiable waxy matter and 



LINEN. 183 

moisture in linen is about the same as in cotton ; in fact, all vege- 
table fibres appear to contain approximately the same amount 
(from 8 to 10 per cent.). 

Due to differences in structure, linen is more easily disinte- 
grated than cotton, and consequently does not withstand the 
action of boiling alkahne solutions, solutions of bleaching pow- 
der or other oxidizing agents, etc., as well as cotton. 

Towards mordants and dyestuffs, etc., linen does not react as 
readily as cotton, hence its manipulation in dyeing is more diffi- 
cult. In general, however, it may be said that the dyeing and 
treatment of linen are practically the same as with cotton. 

The oil-wax group of constituents in the flax fibre plays an 
important part in the spinning of this fibre, and the failure of 
many of the artificial processes of retting flax may be attributed 
to the fact that the fibre is left with a deficiency of these constitu- 
ents. In the breaking down of the cuticular celluloses, whether 
in the retting or in the bleaching processes, these waxes and oils 
are separated. Their complete elimination from the cloth neces- 
sitates a very elaborate treatment, such as is represented by the 
"Belfast Linen Bleach." 

18.68 per cent, of saponifiable oil. Of the latter, 54.49 per cent, is free fatty 
•acid. The waxy matter has a melting-point of 68° C, and apparently is a mixture 
of several bodies. The principal one resembles ceresin, and there is also present 
ceryl alcohol and phylosterin. The saponifiable matter appears to contain small 
quantities of soluble fatty acids, Like caproic, stearic, palmitic, oleic, linolic, linolenic, 
and isolinolenic. 



CHAPTER XV. 

JUTE, RAMIE, HEMP, AND MINOR VEGETABLE FIBRES. 

I. Jute is a fibre obtained from the bast of various species of 
Corchorus, growing principally in India and the East Indian 
Islands. The most important variety is Corchorus capsularis,. 
which is grown throughout tropical Asia not only as a fibre-plant,, 
but also as a vegetable. Other varieties are C olitorius, C. juscus, 
and C. decemangulatus ; the latter two, however, yield but a small, 
proportion of the jute fibre to be found in trade.* The jute 
plant grows to a height of lo to 12 ft. and its fibrous layer is very- 
thick, so that it yields from two to five times as much fibre as flax. 

The preparation of the fibre from the jute plant is a rather 
simple operation. The stalks are freed from leaves, seed-cap- 
sules, etc., and retted by steeping in a sluggish stream of water. 
After a few days the bast becomes disintegrated, and the retted 
stalks are pressed and scutched. The fibre so obtained is re- 
markably pure and free from adhering woody fibre and other 
tissue. The prepared fibre usually has a length of from 4 to 7 ft., 
possesses a pale yellowish brown color, and exhibits considerable 
lustre and tensile strength. The ends of the plant, together with 
the various short waste fibres, appear in trade under the name of 
"jute butts" or "jute cuttings," and are employed as a raw ma- 
terial for paper-manufacturing. 

* The commercial fibre known as Chinese jute is not a variet)' of jute at all, 
but is derived from Abutilon avicennm or Indian mallow. The latter grows 
extensively as a weed in America. The bast fibre is white and glossy, and has- 
considerable tensile strength. It is also used for the making of paper stock. 
Chemically it appears to consist of bastose, and hence resembles jute in its behavior 
towards dyestuffs. The plant produces about 20 per cent, of fibre, but is of doubt- 
ful economic value. 

184 



JUTE, RAMIE, HEMP, AND MINOR. yEGETABLE FIBRES. 185 



5 3 1 



2 4 



According to Hohnel the bast-cells of the jute fibre are 1.5 to 
5 mm. in length, and from 20 to 25 // in thickness, the mean 
ratio of the length to the breadth being 
about 90 ; consequently the elements of the 
jute fibre are relatively short. In cross- 
section the jute fibre shows a bundle of 
several elements bound together; these are 
more or less polygonal in outline, with 
sharply defined angles. Between the sepa- 
rate elements is a narrow median layer 
(see Figs. 40 and 41), which, however, does 
not give a much darker color with iodin and 
sulphuric acid than the cell-wall itself. 
The lumen is about as wide, or at times 
even wider, than the cell-wall, and in cross- 
section is round or oval. Longitudinally, 
the lumen shows remarkable constrictions 
(see Fig. 39), though towards the end of 
the fibre the lumen broadens out consider- 
ably, causing the cell-wall to become very 
thin. Externally the fibre is smooth and 
lustrous, and has no jointed ridges or 
transverse markings such as seen in linen or 
most other bast fibres. 

In its chemical composition jute is apparently quite different 
from linen and cotton, being composed of a modified form of 
cellulose known as lignocellulose or bastose. Bastose, properly 
speaking, is a compound of cellulose with hgnin.* It behaves 
quite differently from celullose towards various reagents, its chief 
distinction being that it is colored yellow by iodin and sulphuric 
acid, whereas pure cellulose is colored blue. The following table 
gives the principal reactions used to distinguish cellulose from 
bastose : 




Fig. 38. — ^Diagram of 
Flax-straw. (Witt.) 
I, marrow; 2, woody 
fibre; 3, cambium 
layer; 4, bast fibre; 5, 
rind or bark. 



* Miiller gives the following method for the isolation of pure cellulose from 
jute: Two grams of the material are dried at 110° to 115° C. In order to remove 
wax, etc., it is next treated mth a mixture of alcohol and benzol, and is subse- 
quently boiled with very dilute ammonia water. The softened mass is then 



i86 



THE TEXTILE FIBRES. 



Reagent. 

lodin and sulphuric acid 
Anilin sulphate and sul- 
phuric acid 

Basic dyestuffs 

Weak oxidizing agents . . 
Schweitzer's reagent, . . . 



Cellulose. 



Bastose. 



Blue color 

No change 
No change 
No change 
Quickly dissolves 



Yellow to brown color 

Deep-yellow color 
Becomes colored 
Quickly decomposes 
Swells, becomes blue, and slowly 
dissolves 



Analysis of the jute fibre shows it to consist of the following: 



Constituents. 



Ash 

Water (hygroscopic) 

Aqueous extract 

Fat and wax 

Cellulose 

Incrusting and pectin matters 



Nearly Color- 


less Specimen. 


O 


68 


9 


93 


I 


03 


o 


39 


64 


24 


24 


41 



Fawn-coloi-ed 
Fibre. 



.64 
■63 
•32 
•05 
•36 



Brown 
Cuttings. 



12.5s 

3-94 

0.45 

61.74 

21 . 29 



The ash of jute consists principally of silica, lime, and phos- 
phoric acid; manganese is nearly always present in small 
amount.* 

Bastose is dissolved by the usual cellulose solvents, such as 
zinc chloride and Schweitzer's reagent; and from these solutions 
the lignocellulose may be precipitated by dilution or acidifying, 
respectively, though the precipitation is never complete, there 
remaining in solution about 15 to 25 per cent, of 
substance. 



the original 



pulverized in a mortar, and placed in a large, glass-stoppered flask with 100 c.c. 
of water. From 5 to 10 c.c. of a solution of 2 c.c. of bromin in 500 c.c. of water 
are added, until a permanent yellow color is obtained after standing twelve to twenty- 
four hours. The substance is then filtered, washed with water, and heated to 
boiling with water containing a little ammonia. After this it is filtered, washed, and 
again treated with the bromin solution, as above indicated, until a permanent 
yellow color is obtained. The fibre is then boiled with dilute ammonia, and on 
filtering and washing leaves a residue of pure white cellulose. 

* According to Cross and Bevan the jute fibre may be regarded as an anhydro- 
aggregate of three separate compounds: (a) A dextrocellulose allied to cotton; 
(6) a pentacellulose yielding furfural and acetic acid on hydrolysis; (c) lignone, 
a quinone which is converted by chlorination and reduction into derivatives of 
the trihydric phenols. 



JUTE, RAMIE, HEMP, AND MINOR yEGETABLE FIBRES. 187 

The chief chemical difference between jute and the pure cel- 
lulose fibres is in the ability of the former to combine directly 
with basic dyestuffs. In fact, it acts in this respect similar to 




Fig. 39. — Cross-section of Flax-straw. (Cross & Bevan.) 
A, layer of cuticular cells; B, intermediate layer of cortical parenchyma; C, bast 
fibres in groups, being the flax fibres proper; note secondary thickening of 
cell-walls; D, cambium layer; E, woody tissue. 



cotton which ^has been mordanted with tannic acid. Jute is also 
more sensitive to the action of chemicals in general than cotton or 
linen. On this account it cannot be bleached with much success, 
as treatment with alkalies and bleaching powder weakens and 
disintegrates the fibre to a considerable extent. 



1 88 THE TEXTILE FIBRES. 

The jute fibre is relatively weak when compared with other 
bast fibres, and the chief reasons for its prominence among the 
textile fibres are its fineness, silk-like lustre, and adaptability for 
spinning. The plant is also easy to cultivate, and returns a large 
yield of fibre. The chief defect of jute is its lack of durability; 
when exposed to dampness it rapidly deteriorates; and even under 
ordinary conditions of wear, the fibre gradually becomes brittle 
and loses much of its strength. The bleached fibre is especially 
liable to such deterioration; it gradually loses its whiteness, and, 
evidently due to oxidation, becomes dingy and yellowish brown 
in color. 

Jute is principally used for the making of coarse woven fabrics, 
such as gunny sacks and bagging, where cheapness is of more 
consequence than durability. It also finds considerable use in 
the tapestry trade, being used as a binding-thread in the weaving 
of carpets and rugs. On account of its high lustre and fineness, 
it is also adapted for the preparation of cheap pile fabrics for use 
in upholstery. Of late years a variety of novelty fabrics for dress- 
goods have also been made from jute, used in conjunction with 
woolen yarns. Jute has also been used extensively as a substitute 
for hemp, for which purpose the former is rendered very soft and 
pliable by treatment with water and oil. A mixture of 20 parts 
of water with 2.5 parts of oil is sprinkled over 100 parts of jute 
fibre. It is left for one to two days, then squeezed and heckled, 
whereby the fibres become very soft and isolated. Jute is also 
largely used in the manufacture of twine and smaller sizes of 
rope. Owing to its cheapness it is used to adulterate other more 
valuable fibres, but due to its tendency to rapid deterioration, its 
use in this connection should not be encouraged. The "jute 
butts" and miscellaneous waste are extensively employed as a 
raw material in the manufacture of paper. 

2. Ramie, or China Grass, is a fibre obtained from the bast of 
the stingless nettle, or Boehmeria. Although frequently con- 
founded in trade, ramie and China grass are in reality two dis- 
tinct fibres. The former (also known as rhea) is obtained from 
the Boshmeria tenacissima, which grows best in tropical and sub- 
tropical countries. The latter is obtained from Boehmeria nivea, 
which grows principally in the more temperate cHmes. The 



JUTE, RAMIE, HEMP, AND MINOR l^EGETABLE FIBRES. i89 

two species, however, are so similar in nature, and the fibres are 
so universally confounded with one another, that it is only possi- 
ble to consider them as a single substance, which will be done 
under the name of ramie. The plant is a shrub, reaching 4 to 
6 ft. in height, and is very hardy. It is cultivated largely 
in China and India, and has also been grown successfully in 
America. 

The fibre of ramie is very strong and durable, probably rank- 
ing first of all vegetable fibres in this respect. It is also the least 
aflfected by moisture. It has three times the strength of hemp, 
and the fibres can be separated to almost the fineness of silk. 
The fibre is exceptionably white in color, being almost compa- 
rable to bleached cotton in this respect, and does not appear to 
have any natural coloring-matter at all. It also has a high lustre, 
excelling linen in this respect. 

The following table gives the chief physical factors of the ramie 
fibre in comparison with the other principal fibres: 





Ramie. 


Hemp. 


Flax. 


Silk. 


Cotton. 


Tension 


100 
100 
100 


36 

75 
95 


25 
66 
80 


13 
400 
6co 




Elasticity 


100 

40O 


Torsion 





Having such excellent quahties as a fibre, it would be natural 
that ramie should have had considerable attention bestowed upon 
it. The chief difficulty in the way of its universal and wide-spread 
adoption has been the lack of an efficient process for properly 
decorticating the fibre from the rest of the plant. In China and 
India, where this fibre has long been employed for the weaving of 
the finest and most beautiful fabrics, the decortication of the 
fibre is carried out by hand. This, of course, would be imprac- 
ticable in western countries. 

On French authority it is stated that the yield of decorticated 
fibre from the green, unstripped stalks amounts to about 2 per 
cent., and of degummed fibre about i per cent. Based on the 
weight of dr)% stripped stalks, the yield of the degummed fibre 
would be about 10 per cent. 



190 



THE TEXTILE FIBRES. 



The bast of the ramie cannot be removed from the woody 
tissue in which it is imbedded by a simple retting, as in the case of 
flax and other bast fibres. It must undergo a severe mechanical 
treatment, whereby the outer bark is removed. The long, fibrous 
tissue so obtained consists of the ramie filaments held together in 
the form of a ribbon by a large quantity of gum, and before the 
fibres can be combed out this gum must be removed by chemical 
treatment. The gummy matters seem to consist esssentially of 
pectose, cutose, and vasculose. In the degumming, the object is 
to remove these substances without affecting the cellulose of the 
fibre proper. The vasculose and cutose may be dissolved by 
treatment with alkaline oleates or caustic alkalies employed 
under pressure. The adhering pectose can then be detached 
mechanically by washing. 

Though ramie has many excellent qualities to recommend it 
as a textile fibre for definite uses, nevertheless it lacks the elas- 




FiG. 40. — Jute Fibre. 
A, middle portion; B, end of fibres; /, lumen; k, knot-like joints; 
sections; m, median layers between fibres. 



C, cross- 



ticity of wool and silk and the flexibility of cotton. As a result 
it yields a harsher fabric, which has not the softness of cotton. 
Owing to its smooth and regular surface it also becomes difficult 
to spin into fine counts, as the fibres lack cohesion and will not 
adhere to each other. 



JUTE, RAMIE, HEMP, AND MINOR VEGETABLE FIBRES. 191 

Microscopically, the ramie fibre is remarkable for the large 
size of its bast-cells. These are from 60 to 250 mm. in length and 
up to 80 fi in width. The ratio of the length to the breadth is 
about 2400. The fibre consists of pure cellulose with no indica- 
tion of the presence of any hgnin. Along the fibre, joints and 
transverse fissures are of frequent occurrence (see Fig. 42). The 
lumen is especially broad and easily noticeable. The ends of the 
fibre elements have a thick- walled, rounded point, and the lumen 
is reduced to a line. The cross-section of the fibre (see Fig. 43) 
shows usually only a single element or a group of but a few mem- 
bers. The cross-section is also quite large, and is elhptical in 
shape; the lumen appears open, and frequently contains granular 
matter. The cross-section also frequently shows strong evi- 
dence of stratification. The fibres are frequently very broad, 
and at these parts are flat and ribbon-like in form, but are never 
twisted (see Fig. 44). 

Miiller gives the following analysis of the raw fibre of samples 
of both China grass and ramie: 



Constituent. 

Ash 

Water (hygroscopic) 

Aqueous extract 

Fat and wax 

Cellulose 

Intercellular substances and pectin 



China 
Grass. 



Ramie. 



2.87 

9-05 
6.47 
0.21 
78.07 
6. 10 



5-63 
10. 15 

10.34 

0-59 

66.22 

12.70 



3. Hemp is a name appHed to a large number of bast fibres 
more or less analogous in appearance and properties.* Hemp 

* Among the different varieties of hemp appearing in trade may be enumerated 
the following (Dodge): 

Ambari (or brown) hemp Hibiscus cannahinus 

Bengal (or Bombay) hemp Crotalaria juncea 

Black-fellow's hemp Commersonia fraseri 

Bowstring hemp (Africa) Sansevieria guineensis 

Bowstring hemp (India) S. roxhurghiana 

Bowstring hemp (Florida) 5. lojtgiflora 

Calcutta hemp Juie 

Cebu hemp Musa textilis 

Colorado River hemp Sesbania macrocarpa 



192 THE TEXTILE FIBRES. 

proper, or the so-called common hemp, is derived from the bast 
of Cannabis sativa. This is a shrub growing from 6 to 15 ft. in 
height, and though originally a native of India and Persia, it is 
now cultivated in nearly all the temperate and tropical countries 
of the world. At the present time it is quite extensively grown 
in America, though not as yet in sufficient amount to satisfy the 
home consumption. Russia produces an enormous quantity of 
hemp; in fact, this fibre forms one of that country's staple articles 
of export. Poland is also a large producer. French hemp, 
though not grown to such an extent, is much superior in quality 
to that from either Russia or Poland, it being fine, white, and 
lustrous. Italian hemp is also of a very high grade. In India 
hemp is not grown so much for its fibre as for the narcotic 
products obtained. Japanese hemp is of excellent quality, and 
appears in trade in the form of very thin ribbons, smooth and 
glossy, of a light straw color, and the frayed ends showing a fibre 
of exceeding fineness. Hemp appears to have been the oldest 
textile fibre used in Japan. 



Cretan hemp Datisca cannabina 

Cuban hemp Furcrcea cuhensis 

False hemp (American) Rhus typhina 

False sisal hemp Agave decipiens 

Giant hemp (China) Cannabis gigantia 

Hayti hemp Agave fcetida 

Ife hemp Sansevieria cylindrica 

Indian hemp Apocynum cannabinum 

Jubbulpore hemp (Madras) Crotalaria tennifolia 

Manila hemp -. Mtisa textilis 

New Zealand hemp (or flax) Phormium tenax 

Pangane hemp Sansevieria kirkii 

Pita hemp Yucca spp. 

Pua hemp (India) Maoutia puya 

Queensland hemp Sida retusa 

Rangoon hemp Laportea gigas 

Roselle hemp Hibiscus sabdariffa 

Sisal hemp Agave rigida 

Sunn hemp Crotalaria juncea 

Swedish hemp Urtica dioica 

Tampico hemp Agave heteracantha 

Water hemp Eupatorium cannabinum 

Wild hemp Maoutia puya 



JUTE, RAMIE, HEMP, AND MINOR t^E GET ABLE FIBRES. I93 

The hemp fibre is obtained from the plant by a process of 
retting similar to that employed for flax. The method of dew- 
retting is chiefly used; that is, the stalks are spread out in the 
fields until the action of the elements causes the woody tissue 
and gums enclosing the fibres to decompose. Retting in pools 




Fig. 41. — Cross-section of Jute-straw. (Cross & Bevan.) 

Showing transverse section of portion of bast only, giving the anatomy of the 

fibrous tissue, the form of the bast-cells, and the thickening of the cell-walls. 

of water has been practised to a slight extent, but evidently not 
with much success. It is said that 100 kilos of raw hemp furnish 
25 kilos of raw fibre or filasse; and 100 kilos of the latter yield 
65 kilos of combed filasse and 32 kilos of tow. 

The seed of the hemp. plant, like that from flax, is also utilized 
for the oil it contains; 100 kilos of seed furnish 27 kilos of oil. 



194 



THE TEXTILE FIBRES. 



So this forms an extensive and important by-product in the culti- 
vation of hemp. 

Under the microscope the hemp fibre is seen to consist of 
cell elements which are unusually long, averaging about 20 mm. in 
length, but varying from 5 to 55 mm. The diameter, however, 
is very small, averaging 22 ja, and varying from 16 to 50 /x. Hence 
the ratio between the length and diameter is about 1000. The 




Fig. 42. — Ramie Fibre. (Hohnel.) 

V, swollen displacements; r, fissures; e, point or end; q, cross-sections; i, inner 

layers of fibre- wall; /, lumen; sch, stratifications. 



fibre is rather uneven in its diameter, and has occasional attach- 
ments of fragmentary lignified tissue. In its linear structure the 
fibre exhibits frequent joints, longitudinal fractures, and swollen 
fissures. The lumen is usually broad, but towards the end of 
the fibre it becomes like a line (see Fig. 45.) It shows scarcely 
any contents. The ends of the filaments are blunt and very 
thick-walled, and often possess lateral branches. The cross- 
section generally shows a group of cells which nearly always have 
rounded edges and are not so sharp-angled and polygonal as in 



lUTE, RAMIE, HEMP, AND MINOR (VEGETABLE FIBRES. 195 



the case of jute. There is also a median layer between the cells, 
which is evidenced by it turning yellow on treatment with iodin 
and sulphuric acid. In the section the lumen appears irregular 
and flattened, and does not show any contents. The cell-walls 
frequently exhibit a remarkable stratification, the different layers 




Fig. 43. — Cross-section of Ramie-straw. (Cross & Bevan.) 
Showing transverse section of bast region only; the bast fibres are to be distin- 
guished by their large area from the adjacent tissue. 

yielding a variety of colors on treatment with iodin and sul- 
phuric acid (see Fig. 46). 

Hemp is somewhat difficult to distinguish microscopically from 
flax; but the two may readily be told by an examination of the 
ends of the fibres, hemp nearly always exhibiting specimens of 
forked ends, whereas flax never has this peculiarity. The differ- 



lyO THE TEXTILE FIBRES. 

ence in the appearance of the cross-sections is also of service in 
discriminating between these two fibres. Again, the parenchymous 
tissue which frequently occurs as attached fragments to hemp 
fibres is rich in star-shaped crystals of calcium oxalate, and this, 
is scarcely ever to be noticed in the case of flax. A peculiarity to 
be noticed in the examination of hemp is the occasional presence 
of long narrow cells filled with reddish brown matter, insoluble in. 




Fig. 44. — Ramie Fibre (X500). 
Showing the longitudinal ridges and knotted-like cross-markings and fissures. 

the ordinary solvents. These cells occur between the fibres as 
well as in the bast, and probably contain tannin. They are not 
to be found in flax. The behavior of isolated hemp-cells with 
ammoniacal copper oxide solution is also quite characteristic ; the- 
cell membrane acquires a blue to a bluish green color, and swells 
up like a blister, showing sharply defined longitudinal striations. 
The inner cell-wall remains undissolved in the form of a spirally 
wound tube contained inside the strongly swollen mass of the 
fibre. 

The hemp fibre is not composed entirely of pure cellulose, as. 
it gives a green coloration with anihn sulphate, and iodin and 
sulphuric acid. It appears to be a mixture of cellulose and bas- 



JUTE, RAMIE, HEMP, AND MINOR VEGETABLE FIBRES. 197 

tose. Miiller gives the following analysis of a sample of best 
Italian hemp: 

Per Cent. 

Ash 0.82 

Water (hygroscopic) 8.88 

Aqueous extract • 3-48 

Fat and wax 0.56 

Cellulose 77-77 

Intercellular matter and pectin bodies 9-3i 

Hemp is principally employed for the manufacture of twine 
and cordage, for which its great strength eminently adapts it ; and 
besides, it is a very durable fibre, and is not rotted by water. In 
this respect it differs very essentially from jute. It is seldom used, 
however, for woven textiles, as it is harsh and stiff, and not suffi- 
ciently pliable and elastic. It also possesses a rather dark brown 
color, and cannot be successfully bleached without serious injury 
to the quality of the fibre. 

4. Sunn Hemp is the bast fibre of the Crotalaria juncea; it 
is also known by the names of Conkanee, Indian, Brown, and 
Madras hemp. It grows abundantly in the countries of southern 
Asia, and is largely used in the manufacture of cordage. It 
appears to have been one of the earliest fibres mentioned in 
Sanscrit literature. The fibre is obtained from the plant by a 
system of retting very similar to that of flax. The fibre of sunn 
hemp is of a better quahty than jute, being lighter in color, of 
a better tensile strength, and more durable to exposure. Dr. 
Wight gives the following table for the strength of several cordage 
fibres : 

Pounds 

Sunn hemp 407 

Cotton rope 346 

Hemp 290 

Coir 224 

In appearance sunn hemp is very similar to hemp, both to 
the naked eye and under the microscope. The essential distinc- 
tion between the two is in the cross-section (see Fig. 47), which 
shows the presence of a very thick median layer of lignin between 



THE TEXTILE FIBRES. 



the individual cells. The lumen in the cross-section is also 
usually rather thick, and often contains yellowish matter, differ- 




FlG. 45. — Fibres of Hemp (X350). 
Showing longitudinal fissures and numerous transverse cracks and jointed-like 



structure. 



ing in these respects from hemp, in which the lumen is fiat and 
narrow and always empty. 

Miiller gives the following analysis of raw sunn hemp : 

Per Cent. 

Ash 0.61 

Water (hygroscopic) 9 . 60 

Aqueous extract 2.82 

Fat and wax o • 55 

Cellulose 80 . 01 

Pectin bodies 6.41 

5. Ambari or Gambo Hemp is an East Indian fibre derived 
from the bast of Hibiscus cannabinus. The fibre when care- 
fully prepared is from 5 to 6 feet in length; it is of a lighter color 
than hemp, and harsher. Its tensile strength is somewhat less 
than that of sunn hemp. Like the latter fibre, it is principally 
used for cordage, though it is also employed in India for the man- 
ufacture of a coarse canvas. In its microscopic characteristics 
ambari hemp is very similar to jute; the length of the fibre ele- 



JUTE, RAMIE, HEMP, AND MINOR VEGETABLE FIBRES. 199 

ments varies from 2 to 6 mm., and the diameter from 14 to 33 //. 
The median layers of lignin between the cells are broad, and are 
colored much darker than the inner layers of the cell-wall when 
treated with iodin and sulphuric acid. The lumen presents the 
same appearance as with jute (see Fig. 48), having such very 
marked contractions, that in places it is discontinuous. The ends 
of the fibres are very blunt and thick-walled. 

6. New Zealand Flax differs somewhat from the preceding 
fibres in that it is derived, not from the bast, but from the leaves 
of Phormium tenax. Botanically these are known as sclerenchy- 
mous fibres. Apart, however, from this histological difference, 
such fibres are very similar in general structure to ordinary bast 
fibres. Phormium tenax is a native of New Zealand, but is also 
found distributed in other portions of Australasia; it has been 
introduced into several European countries, and is also cultivated 
to quite an extent in California. The fibre of New Zealand flax 
is very white in color, is soft and flexible, and possesses a high 
lustre. In tenacity the fibre appears to be superior to either flax 
or hemp, as is seen by the following comparative figures (Royle) : 

Pounds. 

New Zealand flax 23.7 

Flax 11-75 

Hemp 16.75 

The leaves of Phormium tenax reach over 5 feet in length, and 
the fibre is separated by first scraping the leaves and then comb- 
ing out the separate fibres. No process of retting is necessary, as 
with the bast fibres. The method of preparing the fibre, how- 
ever, is as yet very unsatisfactory, and could be much im- 
proved. The amount of fibre obtained under the present method 
of operating is from 10 to 14 per cent, on the weight of the leaves, 
although the latter contain as much as 20 per cent, of fibre. 

In their microscopical characteristics the fibres of New Zea- 
land flax are remarkable for their slight adherence. The fibre ele- 
ments are 5 to 15 mm. in length and 10 to 20 fx in diameter, and 
the ratio of the length to the breadth is about 550. They are 
very regular and uniformly thickened, and the surface is smooth, 



200 THE TEXTILE FIBRES. 

exhibiting no markings or jointed sutures. The lumen is very 
apparent, but is generally narrower than the cell-wall and is very 
uniform in its width. The ends are sharply pointed and not 
divided. The cross- section shows rather loosely adhering ele- 
ments (see Fig. 49), and is very round in contour, the lumen being 





Fig. 46. Fig. 47. 

Fig. 46. — ^Hemp Fibre Showing Stratification. (Hohnel.) 

Fig. 47. — -Sunn Hemp. (Hohnel.) 

L, view of middle portion; v, joints; /, lumen; s, pointed ends; q, cross-sections; 

m, outer layer of fibre; i, inner layers. 



either round or oval, and is empty. No median layer of lignin is 
apparent between the elements, though the fibres themselves are 
completely lignified. The purified fibre of New Zealand flax is 
rather difficult to distinguish microscopically from aloe hemp or 
from Sansevieria fibre, except by the rounded and separated cross- 
sections. The fibre also usually contains a substance derived from 
the sap of the leaf which possesses the peculiarity of giving a 
deep-red color with concentrated nitric acid. The composition 
of the fibre is as follows (Church) : 



JUTE, RAMIE, HEMP, AND MINOR VEGETABLE FIBRES. 201 

Per Cent. 

Ash 0.63 

Water 1 1 . 61 

Gum (and other matter soluble in water) 21 .99 

Fat 1 .08 

Pectin bodies i . 69 

Cellulose 63 . 00 

New Zealand jflax is principally employed in the making of 
cordage and twine and floor-matting, though the best fibre can 




Fig. 48. — Gambo Hemp. (Hohnel.) 
e, ends with blunt points and wide lumen; d, lateral branch; /, longitudinal cut- 
ting, with V, interruptions in lumen; q, cross-sections, with L, small lumen; 
m, median layers. 

also be woven into cloth resembling linen duck. It has been used 
extensively in the United States for the making of ' ' staff, ' ' being 
mixed with plaster for this purpose. The chief drawback to the 
fibre of New Zealand flax is its poor resistance to water. 

7. Manila Hemp is the fibre obtained from the leaf-stalks of 
the Musa textilis, a variety of plantain which is a native of the 



202 THE TEXTILE FIBRES. 

Philippine Islands. The fibre is white and lustrous in appear- 
ance, light and stiff in handle, and easily separated. It is also a 
very strong fibre, and of great durabihty. In the Phihppines it 
is known as abaca. The coarser fibres are used for the manu- 
facture of cordage, for which purpose it is eminently suited on 
account of its great strength. The relative strengths of rope made 
from EngUsh hemp and that made from Manila hemp are about 
ID to 12 respectively. The finer fibres, which require to be 
selected and carefully prepared, are woven into a very high grade 
of muslin, which brings a good price, even in Manila. Under the 
microscope Manila hemp shows fibre elements of 3 to 12 mm. in 
length, and 16 to 32 p. in width, the ratio of the length to the 
diameter being about 250. The bundles of fibres are very large, 
but by treatment with an alkaline bath are easily separated into 
smooth, even fibres. The fibres are very uniform in diameter, are 
lustrous, and are rather thin-walled. The lumen is large and 
distinct, but otherwise the fibre does not exhibit any markings. 
The cross-sections are irregularly round or oval in shape, and the 
lumen in the section is open and quite large and distinct (see 
Fig. 50). The fibre-bundles frequently show a series of peculiar, 
thick, strongly silicified plates, known as stegmata. Lengthwise 
these appear quadrilateral and solid, and have serrated edges and 
a round, bright spot in the centre. The stegmata may be best 
observed after macerating the fibre-bundles in chromic acid solu- 
tion; they are about 30 p. in length. On extracting the fibre with 
nitric acid, then igniting, and adding dilute acid to the ash so 
obtained, the stegmata will appear in the form of a string of pearls, 
frequently in long chains with sausage-like hnks, a very peculiar 
and characteristic appearance. The lumen often contains a 
yellowish substance, but no distinct median layer is perceptible 
between the fibres. Manila hemp is a lignified fibre, and gives 
a yellow color with anilin sulphate; iodin and sulphuric acid give 
a golden-yellow to a green color; ammoniacal copper oxide causes 
a blue coloration and a slight swelling.* According to Miiller the 
composition of Manila hemp is as follows : 

* Besides the Musa textilis, the fibre from the following varieties is also utilized: 
Musa paradisiaca, M. sapientium, and M, mindanensis from India and islands 
in the Pacific Ocean; M. cavendishii from China; M. eusete from Africa. 



JUTE, Ry4MIE, HEMP, AND MINOR VEGETABLE FIBRES. 203 

Per Cent. 

Ash 1 . 02 

Water 11.85 

Aqueous extract o-97 

Fat and wax o ■ 63 

Cellulose 64 . 72 

Incrusting and pectin matters 21 .83 

8. Sisal Hemp is the fibre obtained from the leaves of the 
Agave rigada, a native of Central America; it is also grown in the 
islands of the West Indies and in Florida. The fibre has a light 
yellowish color, and is very straight and smooth; it is principally 
used for making cordage, for which purpose it is quite valuable, 
as it is second only to Manila hemp in tensile strength. The fibre 
is easily separated from the leaf, and does not require a retting 
process. In their microscopical appearance the fibre-bundles 
often show an interlaced formation with a peculiar spiral thick- 
ening. The fibre elements are 1.5 to 4 mm. in length, and 20 
to 32 fi in breadth, the ratio of the length to the diameter being 
about 100. They are usually quite stiff in texture, and show a 
remarkable broadening towards the middle. The width of the 
lumen is frequently greater than that of the cell-wall. The ends 
are broad, blunt, and thick, but seldom forked. The cross-sec- 
tions are colored yellow by iodin and sulphuric acid, and show no 
evidence of a median layer between the elements. The sections 
are polygonal in outline, but often have rounded edges, and the 
bundles are usually close together. The lumen in the cross- sec- 
tion is large, and polygonal in shape, though the edges of the 
lumen are more rounded than those of the walls. The ash ob- 
tained from the ignition of the fibre shows the presence of glisten- 
ing crystals of calcium carbonate, which are derived from the 
original crystals of calcium oxalate to be found clinging to the 
fibre-bundles. They are usually in longitudinal series, about 
0.5 mm. long, and taper off at the ends to a chisel shape, resem- 
bling a thick needle in form, but having a quadrilateral cross- 
section. 

9. Aloe Fibre, or Mauritius hemp, is obtained from the leaf of 
various species of aloe plants, growing in tropical climates. This 
fibre is often confounded with that of the Agave americana, but 



204 



THE TEXTILE FIBRES. 



it is of different origin. Aloe fibre, however, is very similar to 
Sansevieria fibre, and is hardly to be distinguished from it in 
either physical or microscopic appearance. The fibre elements 
are 1.3 to 3.7 mm. in length, and 15 to 24 fx in breadth. Although 




-^ 



"^777777^^^^777^ 




"«!> 





<=wo 



Fig. 49. — ^New Zealand Flax. 
P, view of pointed ends; L, view of middle portion; S, cross-sections. 



uniformly broad, the cell-wall is thin. The fibres are usually 
cylindrical and not flattened; they show occasional fissure-like 
pores (see Fig. 51). The cross-sections are polygonal, with slightly 
rounded edges. The lumen is usually somewhat broader than 
the walls, and in the cross-section is polygonal, with rounded sides. 
In the Sansevieria fibre the lumen in the cross-section is usually 
larger, and the cell- walls consequently thinner; furthermore the 
lumen has a sharp-edged, polygonal form (see Fig. 51). 

10. Pita Fibre is obtained from the leaf of the Agave americana, 
or century plant; it is also known as aloe fibre. The fibre is 
white to pale straw in color, is stiff and short, has a rather 
thin wall, and furthermore is liable to rot. The fibres have a 
distinctive wavy appearance, and another peculiarity is its great 
elasticity. According to Royle, Indian pita has been found 



JUTE, RAMIE, HEMP, AND MINOR l^EG STABLE FIBRES. 205 






Fig. 50. — Manila Hemp. (Hohnel.) 
5, cross-sections; /, lumen without contents; /, lumen containing granular mat- 
ter; a, silicious skeleton of the stegmata; b, rows of stegmata, flat side; c, 
the same, narrow side. 



A. 



B. 




Fig. 51. — Aloe Fibre. (Hohnel.) 
A, from Aloe speciosus; B, from Sansevieria. e, ends; /, longitudinal view; 
q, cross-sections; r, fissure-like pores in cell-walls. 



2o6 THE TEXTILE FIBRES. 

superior in strength to either coir, jute, or sunn hemp, the break- 
ing- strain on similar ropes made of these materials teing as 
follows : 

Pounds. 

Pita 2519 

Coir 2175 

Jute 2456 

Sunn hemp 2269 

Russian hemp and pita, on comparison, gave a relative strength 
of 16 to 27. Besides its use as a cordage fibre, pita is also em- 
ployed for the making of a very delicate and beautiful lace known 
as Fayal. In its microscopical characteristics pita is very sim- 
ilar to sisal hemp. 

11. Pineapple Fibre, or Silk Grass, is obtained from Ananas 
sativa, or pineapple plant. This fibre has great durabiUty and is 
unaffected by water. It is very fine in staple and highly lustrous, 
and is white, soft, and flexible. It is used in the manufacture of 
the celebrated pirn cloth in the PhiHppine Islands. According 
to Taylor, a specimen of this fibre was subdivided to one ten- 
thousandth of an inch in thickness, and was considered to be the 
most delicate in structure of any known vegetable fibre. Micro- 
scopically it is distinguished from all other leaf fibres, in fact, by 
the extreme fineness of its fibre elements. These are 3 to 9 mm. 
in length and 4 to 8 /^ in thickness. The lumen is very narrow 
and appears like a fine. The cross-sections are polygonal in out- 
line and frequently flattened. - The sections for mcompact groups 
which are often crescent-shaped, and are enclosed in a " thick 
median layer of lignified tissue. 

12. Coir Fibre is obtained from the fibrous shell of the cocoa- 
nut. The fibre occurs in the form of large, stiff, and very elastic 
filaments, each individual of which is round, smooth, and some- 
what resembhng horsehair. It possesses remarkable tenacity 
and curls easily. In color it is cinnamon-brown. It possesses 
marked microscopical characteristics; the fibre elements are short 
and stiff, being 0.4 to i mm. in length and 12 to 24 // in diameter; 
the ratio of the length to the thickness is only 35. The cell- wall 
is thick, but rather irregularly so, in consequence of which the 
lumen has an irregular outline, resembling indentations (see Fig. 



JUTE, RAMIE, HEMP, AND MINOR VEGETABLE FIBRES. 207 

52). The points terminate abruptly and are not sharp, and there 
appear to be a large number of pore- canals penetrating the cell- 
wall. On the external surface the fibre-bundles are occasionally 
covered with small lens- shaped, silicified stegmata, about 15 /< in 
breadth. These stegmata fuse together on ignition, giving a blis- 
ter on the ash. If the fibre is boiled with nitric acid previous to 
its ignition, the stegmata then appear in the ash like yeast-cells. 




Fig. 52. — Coir Fibre. 
s, serrations in wall of lumen; p, pores in wall; si, silicious skeleton from stegmata. 

hanging together in the form of round, silicious skeletons. The 
cross- section of the fibre is oval in shape and yellowish brown in 
color, and enclosed in a network of median layers. Coir fibre is 
employed in the South seas instead of oakum for caulking vessels, 
and it is claimed that it will never rot. The principal use for 
coir, however, is for cordage and matting. For cable-making it 
is said to be superior to all other fibres on account of its lightness 
and great elasticity. Wright gives the following tests on various 
cordage : 

Pounds. 

Hemp 190 

Coir 224 

Bowstring hemp 316 



CHAPTER XVI. 

QUALITATIVE ANALYSIS OF THE TEXTILE FIBRES. 

1. In a commercial examination of manufactured yarns, 
fabrics, etc., it will only be necessary to distinguish between wool, 
silk, cotton, linen, jute, hemp, and ramie. Under wool must 
also be included analogous animal hairs, such as mohair, cash- 
mere, etc. Other animal fibres, such as cow-hair and horsehair, 
may easily be distinguished even by the naked eye. Of course 
there are numerous other fibres of vegetable origin which are 
employed more or less for textile materials, but either they are 
not liable to occur in conjunction with wool, or they may be readily 
distinguished from the latter without requiring a special exami- 
nation. 

The best method of distinguishing qualitatively between the 
various fibres above mentioned is by the use of the microscope, 
whereby their characteristic physical appearance may be readily 
observed. Each of the fibres in question presents certain micro- 
scopical pecuHarities, so that no difficulty is encountered in dis- 
tinguishing between them. The difference in the microscopical 
appearance of these fibres may be comparatively observed by 
reference to the figures given in the preceding pages. 

2. Qualitative Tests. — A rough physical test to distinguish 
between animal and vegetable fibres is to burn them in a flame. 
Vegetable fibres burn very readily and without producing any 
disagreeable odor; animal fibres, on the other hand, burn with 
some difficulty and emit a disagreeable empyreumatic odor re- 
sembling that of burning feathers. The burnt end of the fibre 
is also characteristic, vegetable fibres burning off sharply at the 
end, whereas animal fibres fuse to a rounded, bead-like end. 

208 



QU^LITATiyE yihlALYSlS OF THE TEXTILE FIBRES. 209 

Tables I and II exhibit the characteristic chemical reac- 
tions of the principal fibres, and by suitably employing these 
tests the various fibres may be easily distinguished from one 
another. 



TABLE I. 



Test. 


Wool. 


Silk. 


Linen. 


Cotton. 


Dyestuff Tests. 

Madder tincture 

Cochineal tincture 


Nil 

Scarlet 

Red 

Dved 

Nil 

Partlv diss. 

Nil 

Violet to brown 

Red to brown 

Black 

Black ppt. 

Swells only 

Undissolved 


Nil 

Scarlet 

Red 

Dyed 

Nil 

Dissolves 

Nil 

Nil 

Nil 

Nil 
No ppt. 

Nil 
Dissolves 


Orange 
Violet 

Nil 

Nil 
Dyed 


Yellow 

Light red 

Nil 


Acid dyes in general. . . . 
Mikado vellow 


Nil 
Dved 


Action of Various 




S.A.I,TS. 
Zinc chloride 


Fibre undiss., vellow color 


Stannic chloride 

Silver nitrate 


Black color 

Nil 


Mercury nitrate(]Millon's) 
Cupric or ferric sulphate . 

Sodium plumbite 

Ammoniacal copper oxide 
Ammoniacal nickel oxide 


Nil 

Nil 

Nil 

Swells and partly dissolves 

Undissolved 



The reagents employed for the tests in the tables may be 
prepared as follows: 

(i) Madder Tincture. — Extract i gm. of ground madder with 
50 c.c. of alcohol, and filter from undissolved matter. 

(2) Cochineal Tincture. — This is made in the same manner 
as the above, using i gm. of ground cochineal insects. 

(3) Fuchsin Solution. — Dissolve i gm. of fuchsin (magenta) 
in 100 c.c. of water, then add caustic soda solution drop by drop 
until the fuchsin solution is decolorized; filter and preserve in a 
well- stoppered bottle. In applying the test with this reagent, 
the mixed fibres are treated with the hot solution, then well rinsed, 
when the animal fibres will be dyed red, the vegetable fibres 
remaining colorless. 

(4) Zinc Chloride Solution. — Dissolve 1000 gms. of zinc 
chloride in 850 c.c. of water, and add 40 gms. of zinc oxide, 
heating until complete solution is effected. 

(5) Stannic Chloride Solution. — This may be prepared by dis- 
solving 15 gms. of stannous chloride (SnClj) in 15 c.c. of concen- 



216 



THE TEXTILE FIBRES. 





















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QU/IUT/iTiyE AN /I LYSIS OF THE TEXTILE FIBRES. 211 

trated hydrochloric acid, then gradually adding 3 gms. of pow- 
dered potassium chlorate (KCIO3). Dilute to 100 c.c. with 
water. 

(6) Silver Nitrate Solution. — 5 gms. of silver nitrate (AgNOg) 
are dissolved in 100 c.c. of water, and preserved in an amber- 
colored bottle. 

(7) Mercury Nitrate, Millon's Reagent. — Dissolve 10 gms. of 
mercur}' in 25 c.c. of nitric acid diluted with 25 c.c. of water at a 
luke-warm temperature. Mix this solution with one of 10 gms. 
of mercury in 20 c.c. of fuming nitric acid. 

(8) Copper Sulphate or Ferric Sulphate. — Dissolve 5 gms. of 
these salts respectively in 100 c.c. of water. 

(9) Sodium Plumhite. — Dissolve 5 gms. of caustic soda in 
100 c.c. of water and add 5 gms. of litharge (PbO), and boil until 
dissolved. 

(10) Ammoniacal Copper Oxide, Schweitzer^ s Reagent. — Dis- 
solve 5 gms. of copper sulphate in 100 c.c. of boiling water, add 
caustic soda solution till the copper compound is completely pre- 
cipitated, wash the precipitate of copper hydrate well, then dis- 
solve in the least quantity of ammonia water. This gives a deep 
blue solution. 

(11) Ammoniacal Nickel Oxide. — Dissolve 5 gms. of nickel 
sulphate in 100 c.c. of water and add a solution of caustic soda 
until the nickel hydrate is completely precipitated ; wash the pre- 
cipitate well and dissolve in 25 c.c. of concentrated ammonia and 
25 c.c. of water. This solution dissolves silk almost immedi- 
ately, but reduces the weight of vegetable fibres only about 0.45- 
per cent., and of wool only 0.33 per cent. 

(12) Caustic Potash or Caustic Soda. — Dissolve 10 gms. of 
the caustic alkali in 100 c.c. of water and filter. 

(13) Sodium Nitroprusside. — Dissolve 2 gms. of the salt in 
100 c.c. of water. 

(14) Lead Acetate. — Dissolve 5 gms. of lead acetate crystals 
(sugar of lead) in 100 c.c. of water. 

(15) Sulphuric and Nitric Acids. — The commercial concen- 
trated acids are employed. 

(16) Chlorin Water. — Water is saturated with chlorin gas 



212 THE TEXTILE FIBRES. 

obtained by acting on pyrolusite (MnOj) with hydrochloric acid. 
The solution should be preserved in amber- colored bottles. 

(17) lodin Solution. — Dissolve 3 gms. of potassium iodide in 60 
c.c. of water, and add i gm. of iodin. Dilute this solution, before 
using, with 10 parts of water. When the reaction is employed 
in connection with sulphuric acid, the latter consists of 3 parts of 
concentrated sulphuric acid, i part of water, and 3 parts of gly- 
cerin. The glycerin has the effect of preventing injury to the 
fibres, and at the same time brings out certain details of the 
structure when the fibres have previously absorbed the iodin. 
The fibres are moistened first with the iodin solution and then 
with the sulphuric acid solution. 

(18) Picric Acid Solution. — Dissolve 0.5 gm. of picric acid in 
100 c.c. of water. 

A delicate reaction * for detecting the presence of vegetable 
fibres in wool is the following: The sample of material under 
examination is well boiled with water to remove any finishing 
materials that might be present and interfere with the reaction. 
Then a small portion of the sample is put in a test-tube with i c.c. 
of water and 2 drops of an alcoholic solution of alpha-naphthol 
and about i c.c. of concentrated sulphuric acid. If vegetable 
fibres are present they will be dissolved and the liquid will acquire 
a deep violet color when shaken; the animal fibres only give a 
yellow to reddish brown coloration but no violet tint. If thymol 
is used instead of alpha-naphthol, a beautiful red coloration will 
be produced in the presence of vegetable fibres. Cross and 
Bevan have devised a delicate test which is serviceable for detect- 
ing the presence of vegetable fibres in fabrics: the sample of the 
cloth is immersed in a solution of ferric chloride and potassium 
ferrocyanide, when any vegetable fibre present will be colored 
blue. 

Lieberman gives a test to distinguish between animal and 
vegetable fibres as follows: The fibres are boiled with a solution 
of magenta which has previously been decolorized by the addi- 
tion of just sufficient caustic soda; then they are well washed and 

* Molisch, Dingl. Polyt. Jour., 1886. 



QUALITATIVE ANALYSIS OF THE TEXTILE FIBRES. 213 

placed in water slightly acidulated with acetic acid. If the libres 
are of animal origin they will be colored a deep pink, whereas 
cotton and linen fibres will be unaffected. 

Both this reaction and the one with picric acid (see Table II) 
are convenient to use when it is desirable to render visible the 
animal fibres in a mixed yarn or fabric. In case of a mixture of 
wool and silk fibres, the wool may readily be shown by placing 
the sample in a very dilute boiling solution of caustic soda con- 
taining a few drops of lead acetate solution. Any wool present 
will be turned brown by this treatment, due to the formation of 
lead sulphide from the sulphur which forms a constituent of this 
fibre. Silk (and also cotton or other vegetable fibre) will not be 
colored. In this test, of course, it will be necessary that the 
sample is undyed, or, at least, that all coloring-matters originally 
present be completely removed. 

Allen * summarizes in the table on page 214 the reactions to 
distinguish silk qualitatively from other fibres. 

3. Distinction between Cotton and Linen. — ^As it is often 
desirable to discriminate between these two fibres, the following 
tests, as suggested by various authorities, are given: 

(i) The fibre is burnt: 

Cotton — burnt end tufted. 
Linen — burnt end rounded. 

(2) The fibre is immersed in concentrated sulphuric acid for 
two minutes, washed well with water, then with dilute ammonia 
water, and dried : 

Cotton — forms a gelatinous mass soluble in water. 
Linen — the fibre is unaltered. 

(3) The fibre is treated vdth an alcohoHc solution of madder 
for fifteen minutes : 

Cotton — becomes bright yellow in color. 
Linen — becomes dull orange-yellow in color. 

(4) The fibre is treated with an alcoholic solution of cochineal 
for fifteen minutes : 

Cotton — becomes bright red in color. 
Linen — becomes violet- red in color. 

* Commer. Org. Anal., vol. IV. 518. 



214 



THE TEXTILE FIBRES. 



Test. 


Silk, Wool, Fur, or Hair. 


Cotton or Linen. 


Heated in a small test- 
tube 


Brittle, carbonaceous residue, 
and odor of burnt feathers. 
Gases and condensed mois- 
ture alkaHne to Htmus 


Charring and smell of 
burning wood. Gases 
and condensed mois- 
ture acid to Utmus 


Boiled on a saturated aque- 
ous solution of picric 
acid and rinsed in water 


Dyed yellow 


Unchanged 


Boiled with Millon's rea- 
gent (see p. 210) 


Red coloration 


No change of color 


Treated with cold nitric 
acid (1.2 sp. gr.) 


Colored yellow 


No change of color 


Moistened with dilute hy- 
drochloric acid and 
dried at 100° C. 


Unchanged 


Becomes rotten 




Sillr. 


"Wool, Pur, or 
Hair. 




Heated to boiling with hy- 
drochloric acid 


Dissolved 


Swells, without 
at once dis- 
solving 


Mostly undissolved 


Boiled with a cone, solu- 
tion of basic zinc chlo- 
ride (see p. 208) 


Dissolved 


Unchanged 


Unchanged 


Treated with cold Schweit- 
zer's reagent (see p. 210) 


Dissolved; not 
precipita ted 
by addition 
of salts 


Undissolved; 
dissolves on 
heating 


Dissolved; solution 
precipitated by addi- 
tion of salts 


Treated in the cold with 
10 per cent, caustic soda 


Undissolved 


Dissolved 


Undissolved 


Boiled with a 2 per cent, 
solution of caustic soda 


Dissolved; so- 
lution not 
darkened by 
lead acetate; 
negative re- 
action Avith 
sodium nitro- 
prusside 


Dissolved; so- 
lution gives 
black or 
brown pre- 
cipitate with 
lead acetate 
and violet 
color with 
sodium nitro- 
prusside 


Unchanged 


Behavior vdth Mohsch's 
test (see p. 211) 


Dissolved, 
with little 
coloration 


U n d i ssolved, 
with yellow 
or brown col- 
oration 


Dissolved, vrfth deep 
violet color 



QUALIT/ITiyE ANALYSIS OF THE TEXTILE FIBRES. 215 

(5) The fibre is immersed in olive oil or glycerin, after pre- 
viously being well dried: 

Cotton — remains opaque and white. 

Linen — becomes translucent by reason of the oil rising by 

capillary action between the individual filaments 

of the fibres. 

(6) The fibre is treated with an alcoholic solution of rosolic 
acid, and then with a concentrated caustic soda solution: 

Cotton — remains colorless. 
Linen — becomes rose-red in color. 

(7) The fibre is treated with iodin and sulphuric acid solu- 
tions (see p. 211): 

Cotton — becomes pure blue in color. 

Linen — gives only a dull blue color. This test is satisfac- 
tory only on unbleached linen. 

(8) A small portion of the sample is placed in a solution of 
equal parts of water and caustic potash ; at the end of two minutes 
the sample is raised with a glass rod and placed between:^ several 
thicknesses of filter-paper to remove the excess of water: 

Cotton — remains white or is a pale, clear yello\Jfci color. 
Linen — becomes dark yellow in color. This testK^adapt^ 
only for white goods. 

(9) Kuhlmann recommends the use of a cold cone 
solution of caustic potash. This causes unbleached o 
shrink and curl up, and to become gray or dirty white in^ 
whereas unbleached linen shrinks more than cotton, and 
a yellowish orange color. 

(10) The fibres are immersed in a saturated solution 
and common salt, and dried. The separate threads are 
ignited : 

Cotton — leaves a black-colored ash. 
Linen — leaves a gray-colored ash. 
4. Distinction between New Zealand Flax (Phormium tenax), 
Jute, Hemp, and Linen. — The following series of tests is recom- 
mended to distinguish between the fibres in question : 

(i) The material is immersed in chlorin water for one min- 
ute, then spread on a porcelain dish, and several drops of ammo- 




2i6 THE TEXTILE FIBRES. 

nia water added. New Zealand flax and jute become at first 
bright red in color, which afterwards changes to dark brown; 
linen and hemp acquire a much lighter shade, such as clear 
brown, orange, or fawn. This method is very good for yarn or 
unbleached cloth, and is particularly well adapted for testing sail- 
cloth. French hemp retted in stagnant water is colored a much 
deeper shade than the same kind of hemp retted in running water; 
in either case the color is much darker than that acquired by 
linen. For testing twine this method is said to give excellent 
results, but in bleached material the difference in the shades pro- 
duced is not very marked. 

(2) To test bleached material, the sample is immersed for 
one hour, at 36° C, in nitric acid containing nitrous oxide. New 
Zealand flax assumes a blood-red color, while linen or hemp is 
tinted pale yellow or rose, according to the method by which it 
were originally retted. 

(3) A sample of the material is heated in concentrated hydro- 
chloric acid. Hemp and linen will not become colored, whereas 
New Zealand flax becomes yellow at a temperature of 30° to 
40° C, then becomes red, brown, and finally black. 

(4) A sample of the material is treated with a solution of 
iodic acid. Hemp and linen are not affected, but New Zealand 
flax acquires a rose-red color. 

(5) Jute is distinguished from New Zealand flax by soaking 
the fibres for two to three minutes in a solution of iodin, and 
then rinsing several times in a i per cent, solution of sulphuric 
acid to remove excess of iodin. Jute acquires a characteristic 
reddish brown color; New Zealand flax becomes clear yellow 
in color; hemp acquires a light yellow color, and linen a blue 
color. It will be found best to untwist the separate threads pre- 
vious to this treatment. For the preparation of the iodin and 
sulphuric acid solutions, see p. 211. 

5. Ligneous Matter (derived from woody tissue) may be 
detected in admixture with other fibres in the following manner: 

(i) On exposing the moistened sample to the action of chlorin 
or bromin, and then treating it with a neutral solution of sodium 
sulphite, a purple color will be produced. 



QUALITATIVE ANALYSIS OF THE TEXTILE FIBRES. 217 

(2) If the sample be moistened with an aqueous solution of 
anihn sulphate, an intense yellow color will be produced. 

(3) If the sample be moistened with a solution of phloro- 
glucinol of h per cent, strength, and then with hydrochloric acid, 
an intense violet-red color will be produced. Solutions of resor- 
cinol, orcinol, and pyrocatechol act in a similar manner. 

(4) Woody fibre when boiled in a solution of stannic chloride 
containing a few drops of pyrogallol gives a fine purple color, 
which is easily seen under a magnifying-glass. 

6. Goodale gives the table on page 218, presenting reactions 
for the principal bast fibres. 

7. Systematic Analysis of Mixed Fibres. — The table by 
Pinchon (p. 219) represents an attempt to give a systematic qual- 
itative analysis of the most important textile fibres. With a due 
degree of caution, this schematic analysis may be employed with 
considerable success, though confirmatory tests should be applied 
to the detection of each fibre indicated. The differentiation 
between the various vegetable fibres given is especially difficult. 

8. Identification of Artificial Silks. — Hassac gives the table 
on page 220, presenting systematic tests to identify the different 
varieties of artificial silks or forms of lustra-cellulose, and also 
the distinction between these latter and true silk. 

9. Distinction between True Silk and Different Varieties of 
Wild Silk. — True silk (from Bomhyx mori) rapidly dissolves (one- 
half minute) in boiUng concentrated hydrochloric acid; Senegal 
silk (from Faidherhia) dissolves in a somewhat longer time, while 
yama-mai, tussah, and cynthia silks require a much longer 
time for complete solution. True silk is also rather easily solu- 
ble in strong caustic potash solution, whereas the other varieties 
of silk are not. The most approved reagent, however, for sepa- 
rating true silk from the wild varieties is a semi-saturated solution 
of chromic acid, prepared by dissolving chromic acid in cold 
water to the point of saturation and then adding an equal volume 
of water. True silk is completely dissolved on boihng in this 
solution for one minute, whereas wild silk remams insoluble. 

Under the microscope true silk can readily be told from vvdld 
silks, as the latter fibres are broad and flat, and show very dis- 



2l8 



THE TEXTILE FIBRES 



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QUALITATiyE ANALYSIS OF THE TEXTILE FIBRES. 219 



O 
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^ 1) 

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to 
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THE TEXTILE FIBRES. 



IDENTIFICATION OF ARTIFICIAL SILKS. 



Reagent 


Natural Silk. 


Collodion Silk. 


Cellulose Silk. 


Gelatin Silk. 


Water 


No change 


Swell up; addition of alcohol or glycerin 
causes contraction again 


Cone, sulphuric 
acid 




Swells rapidly 
and d i s - 
solves 


Gradually be- 
comes thin- 
ner and dis- 
solves 


Only dissolves 
on heating 


Acetic acid 


— 


SHght swell- 
ing 


Slight swell- 
ing 


Dissolves n 
boiling 


Half-saturated 
sol. of chromic 
acid 


Dissolves slovs^- 

ly 


Dissolves in the cold 


Diphenylamin 
and sulphuric 
acid 


— 


Blue color 


— 


— 


Caustic potash, 
40% 


Dissolves with- 
out color 


Swell without dissolving, but 
color liquid yellow 


Dissolves rap- 
idly 


Ammoniacal cop- 
per solution 


— 


Swells quickly 
and dis- 
solves 


Swells slowly 
and d i s - 
solves 


Insoluble; col- 
ors liquid 
violet 


Alkaline copper 
glycerin solu- 
tion 


Dissolves im- 
mediately at 
80° C. tus- 
sah silk dis- 
solves in one 
minute n 
boiling 


Unchanged 


Unchanged 


Dissolves n 
boiling 


lodin in potas- 
sium iodide 


— 


An intense red color which disappears on 
washing 


lodin and sul- 
phuric acid 


Yellow 


Deep violet- 
blue 


Pure blue 


Yellowish 1 
reddish 
brown 


lodin in zinc 
chloride 


Becomes yel- 
low and dis- 
integrates 


Blue-violet 


Gray-blue to 
gray-violet 


Becomes yellow 
and disinte- 
grates 


Ignition 


Odor of burnt 
feathers 


No odor 


No odor 


Odor of burnt 
feathers 



QU/IUTATiyE AN /I LYSIS OF THE TEXTILE FIBRES. 221 

tinct longitudinal striations, which are absent in true silk. Excep- 
tion must perhaps be made with the wild silk from Saturnia 
spini, which can scarcely be told from true silk by a micro- 
scopical examination. With regard to distinguishing between 
the different varieties of wild silks themselves, some valuable 
information may be gained by a determination of their relative 
diameters. Hohnel gives the following values for the greatest 
thickness of the different silks: 

True silk {Bombyx mori) 20 to 25 ^ 

Senegal silk {Faidherbia bauhini) 30 to 35 ju 

Ailanthus silk {Attacus cynthia) 40 to 50 j« 

Yama-mai silk {Anthercea yama-mai) 40 to 50 /i 

Tussah silk {Bombyx selene) 50 to 55 ^ 

Tussah silk {Bombyx mylitta) 60 to 65 ju 

According to Wiesner and Prasch, the breadths of the single 
fibres of different silks are as follows: 

Ailanthus silk 7 to 27, mostly 14 fi 

Yama-mai silk 10 to 45, mostly 23 fl 

Bombyx mylitta 14 to 75, mostly 42 [l 

Bombyx selene 27 to 41, mostly 34 p. 

Senegal silk 12 to 34, mostly 22 pi 

True silk 9 to 21, mostly 13 pL 

True silk, ailanthus silk, and Senegal silk do not show any 
cross- marks, or only very faint indications of such; whereas with 
tussah silk and yama-mai silk the cross-marks are very distinct 
and characteristic. 

The microscopical appearance of the end of the fibre on being 
torn apart also serv^es at times as a useful means of distinguishing 
the variety of silk; true silk, tussah silk, and yama-mai silk 
show scarcely any fraying at the ends; in Senegal silk the fraying 
is very noticeable in almost every fibre; while in ailanthus silk 
about one-half of the number of fibres show a frayed end.* 

* Besides the wild silks mentioned above, there are a few others of lesser im- 
portance, which for the sake of completeness are herewith described: 

I. Saturnia polyphemus, a North American variety; consists of very flat 
fibres, with large air-canals and numerous structural filaments separating at the 
edge of the fibre; coarse lumps of adhering sericin are frequent; well-defined 



222 THE TEXTILE FIBRES. 

By the use of the polariscopic attachment to the microscope, 
considerable differences can be observed in the interference colors 
displayed by the different varieties of silks. It is best to conduct 
these observations under a magnification of 30 to 50 diameters; 
and as the silk fibres are more or less ovoid in section, it must be 
borne in mind that the same fibre will give a different color phe- 
nomenon, depending on whether it is viewed from the narrow 
side or from the broad side. Hence, to obtain trustworthy results, 
the appearance of the same side only of the fibres should be com- 
pared. Also, the appearance of single fibres only, and not of 
crossed fibres, should be taken, Hohnel gives the following 
description of the appearance of the different silk fibres viewed 
in polarized light, the observations being made with a dark field, 
and under a magnification of 30 to 50 diameters: 

I. True silk: (a) broad side, very lustrous, of a bluish or yel 



cross-marks are also frequent. The single fibre is about 33 p. in width; in its 
polariscopic appearance these fibres very much resemble ailanthus silk. 

2. Arryndia ricini; the fibres are even more flattened than the preceding, 
and resemble a thin band or ribbon; large air-canals are of frequent occurrence; 
striations very apparent; the sericin layer is in places very thin, and sometimes 
apparently lacking altogether. The double fibre is about 45 to 55 ^a in width, 
and 4 to 6 ^ thick. At the edge of the fibre frayed ends of structural filaments 
are often apparent. Cross-marks are rather ill-defined, but of frequent occur- 
rence. The sericin layer, though thin, is quite uniformly developed. 

3. Anther aa pernyi has a very flat fibre, resembling a ribbon; it does not 
fray out at the ends, and shows scarcely any single filaments. The double fibre 
measures 60 to 80 ^ in width and 8 to 10 ^ in thickness. Cross-marks are rather 
few and indistinct. The sericin layer is very thin, and in general hardly noticeable. 
Moderately sized air-canals are present. 

4. Saturnia cecropia occurs in Texas. The fibre is also flat and ribbon-like 
in form; the double fibre measures 60 to 90 p. in width and 10 to 15 ^ in thickness; 
air-canals are frequent and large, hence the fibre usually appears rather dark 
under the microscope. The cross-marks are very distinct, and at such points 
the fibre is much broader. The fibre is usually much .frayed out and individual 
filaments are easily distinguished. The sericin layer is quite thin but very uni- 
form. 

5. Attacus lunula has fibres which are not so flat as the preceding. The 
double fibre is 25 to 35 fX in width and 12 to 18 fx in thickness. The air-canals 
are fine and delicate; and the fibre shows but a slight degree of fraying. The 
sericin layer is very thin and finely granulated on the surface; in places, it has 
the form of irregular shreds. The fibre as a whole has a brownish yellow appear- 
ance due to the ochre-yellow color of the sericin layer. 



QUALITATIVE ANALYSIS OF THE TEXTILE FIBRES. 223 

lowish opalescent white; the same color is nearly always to be 
found over the entire breadth; {h) narrow side, exactly similar 
to the preceding. 

2. Yama-mai silk: (a) broad side, generally of a pure bluish 
opalescent white; also darker bluish to almost black tones; 
nearly all of the colors are brilliant; (b) narrow side, shows all 
colors, very brilliant and contrasted; darker and blackish tones 
also occur. 

3. Tussah silk (from Bombyx selene): (a) broad side, shows 
all colors, very brilUant; thickness of the fibre very uneven, 
hence the colors change through the length; the thick parts are 
dark blue and reddish violet, while the thinner parts are yellow 
or orange; {b) narrow side, shows bright red and bright green 
colors, though often but slightly visible; the colors form long 
flecks; often only dark gray to black. 

4. Tussah silk (from Bombyx mylitta): (a) broad side, a 
bluish opalescent white prevailing; also brown, gray, and black 
tones; the colors occur in flecks like preceding, though scarcely 
ever dark blue, but mostly bright orange to red or brown; (b) 
narrow side, color a dull gray with bright red or green flecks; the 
general appearance is very similar to the preceding silk. 

5. Ailanthus silk: (a) broad side, bright yellow or yellow- 
brown to gray-brown colors; (b) narrow side, nearly all colors, 
but rather soft and not very contrasted, seldom very bright, but 
rather dull; short flecks of green, yellow, violet, red, or blue. 

6. Senegal silk: (a) broad side, bright yellowish white, gray 
to brown, seldom bluish white in color; (b) narrow side, faint 
and dull gray, brown, to blackish colors, seldom bright colors. 

10. The following micro-analytical tables are given by Hoh- 
nel for the qualitative determination of vegetable fibres: 

I. TABLE FOR THOSE VEGETABLE FIBRES BOTANICALLY 
DESIGNATED AS HAIR STRUCTURES. 

I . (a) Each single fibre consists of a single cell (see 4). 

(b) Each fibre consists of two cells, namely, a short, thick, 
underlying cell, and an overlying pointed, principal cell. The 



224 THE TEXTILE FIBRES. 

fibres are grayish brown, scarcely 0.5 cm. long; hard, woolly, 
lifeless, thin-walled, but round-stapled. Such fibres form the 
thick upper coating on the leaves of the CycadcB macrozamia of 
New South Wales, and are used as vegetable wool in upholstery. 

(c) Each single fibre consists of a series of cells, hence is a 
cellular fibre. The cells are golden yellow to brown in color, 
generally clinging together, and empty. The fibre as a whole is 
highly lustrous, but very harsh and brittle; very thin- walled, flat, 
and ribbon- shaped; frequently twisted on its axis; broad, and 
0.5 to 2 cms. long. Such fibres form the thick coating on the 
leaves of various ferns (Cibotium) in Asia, Australia, and Chili. 
The material is used for upholstery under the name of pulu. 

(d) Each fibre consists of numerous cells growing side by side, 
or of several series of such; forms the so-called tuft (see 2). 

2. (a) Hairs straight, stiff; white to dirty yellow in color. . (see 3). 

(b) Hairs woolly, tough, brownish violet in color, 4 to 6 mm. 
long; consisting of long cotton-like, flat, twisted, spiral cells, 
the walls of which are frequently thick and undulating; the con- 
tents of the cells moderately abundant, yellow to violet, and in 
part colored red with hydrochloric acid. This fibre covers the 
small, egg-shaped, flattened fruit of the new Holland composite 
Cryptostemma calendulaceum. It is used in Australia as a stuffing 
material. 

(c) Hairs woolly, harsh, reddish yellow in color; the cells are 
very thin- walled, colorless, and generally empty; in places, how- 
ever, filled with a homogeneous reddish-yellow substance; where 
two cells come together side by side there are to be noticed round 
spots. The individual cells are relatively broad, extremely varied, 
and irregularly thick; irregularly bent in places and frequently 
knitted together. This fibre forms the coating of a plant (Hibis- 
cus ?) growing in Cuba; as employed for upholstery materials it 
goes by the name of Majagua. 

3, (a) The hairs are i to 3 cm. long, and on the average are under 
50 p. wide; they consist of two layers of cells which grow into one 
another. The inner walls are rough; the outer walls are thin 
and indented, hence lie close against the inner portion; the sec- 
tion walls are quite noticeable and thick; the tufts end in 2 to 



QUy4LlTATiyE ANALYSIS OF THE TEXTILE FIBRES. 225 

6 pointed, often hook-shaped cells; the end cells show numerous 
pores; weakly Hgnified. This fibre consists of the ripe fruit 
spicula of cotton-grass, Eriophorum anguslifolium, E. laii folium, 
etc Cotton-grass (see Fig. 53}. 




Fig. 53. — Fibres of Cotton-grass or Vegetable Silk (X50). 
The sharp fractures show the brittle nature of the fibres. 

{h) The fibres are 5 mm. long; mean breadth of the tufts 
8 to 16 /£, the widest being under 30 //; the tufts do not end with 
sharp-pointed cells; the section- walls under low magnification 
appear as Uttle knots and are usually quite noticeable. This 
fibre is obtained from the small, lance-Hke fruit of the reed 
mace, TypJia angustifolia, which grows on a small shaft, and 
carries the hairs on the other end. It is used for upholstery and 
other filhng material Reed-mace hair (see Fig. 54). 

4. (a) The fibres are fiat, woolly, frequently twisted in a spiral 
manner on their axes; not hgnified (see 5). 

(b) The fibre is generally cylindrical, stiff, not twisted; some- 
what Hgnified, hence colored red with indophenol or phloro- 
glucol (see 6). 

5. (a) Fibres i to 5 cm. long; white to yellowish brown; 12 
to 42 /J. thick Cotton (see Fig. 55). 

(b) Fibres only 9.5 cm. long; very thin; usually consisting of 
tufts; violet-brown in color. See above under 2 (6). 

Cryptostemma hairs. 

6. (a) The product consists of grassy spigula with a hairy cover- 
ing; the hairs are 5 to 8 mm. long and about 10 to 15 /^ wide; 



226 



THE TEXTILE FIBRES. 



the thickness of the wall of the thick, cylindrical-pointed hairs 
remains rather uniform up to the point it- 
self, hence the latter appears very thick; 
spots are often observed. This fibre is 
upholstery material from Saccharum offici- 
nale Sugar-cane hairs. 

(b) The product consists of short white 
fibres, about 8 to 24 /: in width, and of 
oval, flat fruit- shells, 4 mm. wide and 5 
mm. long; the hairs are broadened at the 
base, hence generally knife- shaped; thick- 
walled, with transverse, fissure-like marks; 
the upper portion of the hair is very thin 
and rough- walled ; colorless; the ends are 
usually blunt and contain a granular matter; 
slightly lignified, especially at the base. 

Poplar cotton. 

(c) The product consists entirely of hairs 
and is almost entirely free from accidental 

impurities Vegetable down and silk. 

7, (a) The fibres have two to five longitudi- 
nal ridges on the walls, which are either 
crescent-shaped or quite flat, running into 

■P,^ , -0 J network at the base; these ridges are broad 

riG. 54. — Reed-mace ' <=• 

Hair. (Hohnel.) and difficult to disccrn in a surface view of 

B, ripe fruit at /; h, hair ,t ci , ,• . ^i 

around fruit; A, por- ^he fibre, yet sometimes very apparent; the 
tion of hair; z, cells; maximum thickness about -iK u; white or 

^, knotted structure. ... ou r-^ 

yellowish in color. These fibres are the seed- 
hairs of Apocyneen and Asclepiadeen. . Vegetable silk (see Fig. 56). 
(b) The fibres are without ridges; transverse ridges frequently 
at the base or as a network. Maximum thickness generally 
under 35 /x; yellowish to brown. These fibres consist, of the 
hairs which cover the fruit-pods of Bombacce. 

Vegetable down (Fig. 59; see 13). 
8. (a) The hairs are 3.5 to 4.5 cm. long, and the largest are 50 to 
60 /x in diameter (see 9). 




QUALITATIVE ANALYSIS OF THE TEXTILE FIBRES. 227 

{h) The fibres are 1.5 to 4 cm. long, and the largest are 35 to 

45 [X in diameter (see 10). 

9, (a) The fibres are narrowed at the base, and directly above 
are strongly swollen, and up to 100 [i in thickness; numerous 




c^(^'r 




Fig. 55. — Cotton Fibres. (Hohnel.) 
a, portion swollen mth Schweitzer's reagent; cf, shreds of cuticle; cr, rings of 
cuticle; ce, cellulose; i, dried protoplasmic canal; b, various cotton fibres 
with sections above; /, lumen; d, twists; s, granulations on cuticle. 



pores at the base; the fibres grow brush-like on a stem, are yel- 
lowish and harsh. This is vegetable silk from Senegal. 

Strophantus (see Fig. 56). 



228 



THE TEXTILE FIBRES. 



(h) The fibres are white, firm, and tough, not harsh; form a 
hairy tuft or crown. This is vegetable silk from India. 

Beaumontia grandiflora (see Fig. 57). 
(c) Yellow rod fibres, weak, stiff, straight, and harsh. 

Calotropis procera, Senegal. 




Fig. 56. — Fibre of Strophantus. 
a, longitudinal view; b, cross-sections. 



10. (a) At the base of the hair there are spots or pores .... (see ii)» 
(b) Spots or pores lacking. Vegetable silk from Asdepias 

cornutii, curassavica, etc (see Fig. 58). 

11. (a) Spots large; round or oblique; the walls of the fibre are 
not thicker at the base than at the upper portion; the ridges on 
the fibre are remarkably well developed, the hairs are strongly 
bent back at the base. Vegetable silk from Calotropis gigantea. 

(b) Spots small, no longitudinal markings; walls thicker than 
the foregoing fibre; ridges less noticeable and often apparently 
lacking (see 12). 

12. (a) Hairs narrowed at the base Hoya viridi flora. 



QUAUTATiyE /tNA LYSIS OF THE TEXTILE FIBRES. 229 

(b) Hairs not narrowed at all, or scarcely so Marsdenia. 

13. (a) The hairs have mesh-hke ridges at the base, situated 
obliquely, or have spiral ridges (see 14). 




Fig. 57. — ^Vegetable Silk from Beaumontia grandi flora. (Hohnel.) 

h, base of fibre; s, pointed ends; q, cross-section; m, middle portion of fibre; 

w, cell-wall; /, longitudinal ridges. 



(b) Without mesh-like ridges at the base (see 15). 

14. (a) Base broader, thin-walled, with obhque, mesh-like ridges 
or spiral swellings, which often extend to a considerable dis- 
tance. Points very thin-walled, gradually tapering, not ended 
sharply ; frequently containing a reddish-brown homogeneous 



^3° 



THE TEXTILE FIBRES. 




Fig. 58. — ^Vegetable Silk from Asclepias cornutii. 
a, longitudinal view; b, cross-sections; r, thickened ridges; w, cell-wall. 




Fig. 59. — Ceiba Cotton. 

a, longitudinal views; r, base of fibre, showing network at n; p, pointed end; 

b, cross-section, showing cell-walls. 



QUAUT/tTIVE ANALYSIS OF THE TEXTILE FIBRES. 231 



granular substance; fibre not very stiff, usually notched. Base con 
tains no marrow. Vegetable down from 
Eriodendron anjractuosum. 

(b) Quite similar, but the ends are 
not so tapering; without marrow; whole 
fibre somewhat rough-walled. Vege- 
table down jrom Bombax hepta- 
phyllum. 

(c) Very similar to (a), but walls 
of fibre are quite roughened, and con- 
tain at intervals throughout its length 
a granular marrow; base thick- walled, 
mesh - like fibrous ridges, but neither 
spirally developed nor very broad — at 
most only one-sixth of the width of the 
fibre; ends, as before, thick- walled. 
Vegetable down, Ceiba cotton, from 

Bombax ceiba (see Fig. 59). 

15. (a) Raw fibre, brown, rough- walled; 
walls 1 to J fj. thick; not indented; 
points without marrow; stiff and very 
sharp at end; base not broadened, often 
contains granular matter. Vegetable yig 
down from Ochroma lagopus. 





lagopus 



60. — Ochroma 
(Hohnel.) 
/ T7'" c \ fn, middle part of fibre; h, 
(see Fig. 60). 'base; s, pointed end; /, 
(6) Raw fibre, yellowish, thin- walled, lumen; q, cross-section; 
. w, cell-wall. 

walls very uneven m thickness; fre- 
quently weakly developed longitudinal ridges; just at the base 
the wall is very thick. Vegetable down from Cochlospernum 
gossypium. 



232 THE TEXTILE FIBRES. 

II. GENERAL TABLE FOR THE DETERMINATION OF THE 
VEGETABLE FIBRES. 

Including cotton, as well as the more important fibres derived 
from bast or sclerenchymous tissues. 

A. Fibres Colored Blue, Violet, or Greenish with lodin and 
Sulphuric Acid. 

(a) Bast fibres and cotton. (Cotton, flax, hemp, sunn 
hemp, ramie, Roa fibre.) 

I. The cross- sections become blue or violet with iodin and 
sulphuric acid; show no yellowish median layer; the lumen is 
often filled with a yellowish marrow. 

1. Cross-sections: they occur either singly or in small groups; 
the single sections do not join over one another; are polygonal, 
and have sharp edges; iodin and sulphuric acid colors them 
blue or violet; they show closely packed, delicate layers; the 
lumen appears as a yellow point. 

Longitudinal appearance: with iodin and sulphuric acid, 
quite blue; it appears transparent, quite uniformly thick; smooth 
or delicately marked; joints frequent; indications of dark lines 
running through, which are usually crossed; enlargements on the 
fibre, especially at the joints, frequent; the lumen apears as a 
narrow yellow line; the natural ends of the fibres are sharply 
pointed; length 4 to 66 mm., thickness 15 to 37 //. 

Linen or Flax (see Fig. 68). 

2. Cross-sections single or very few in a group, loosely held 
together; polygonal or irregular, mostly flat, very large; colored 
blue or violet with iodin and sulphuric acid; stratification not 
noticeable; the lumicn is large and irregular; frequently filled 
with a dark yellow marrow; radial fissures frequently apparent. 

Longitudinal appearance: many of the fibres remarkably 
broad; the width of a single fibre very uneven ; smooth or striped; 
very often ruptures in the wall; with iodin and sulphuric acid, 
blue or violet; the lumen readily seen; very broad, often contain- 
ing a dark yellow marrow; joints noticeable; dark, transverse 
lines frequent, often crossing each other; the ends are relatively 



QUALITATIVE ANALYSIS OF THE TEXTILE FIBRES. 233 

thick- walled and blunt; length 60 to 250 mm., thickness up to 

80 ;« China grass, Ramie (see Fig. 42). 

3. Cross-sections: not many in the groups; polygonal; mostly 
with straight or slightly cun-ed sides and blunt angles; the 
lumen is contracted lengthwise regularly; frequently contains 
a yellow marrow, many sections are surrounded by a thin, green- 
ish-colored layer; not closely joined to one another. The sec- 
tions often show very beautiful radial marks or fissures and con- 
centric layers; the various layers are colored differently. 

Longitudinal appearance, as with China grass; proportional 
dimensions similar Roa fibre (see Fig. 61). 




Fig. 61. — Section of Roa Fibre. 
/, iissures in inner wall. 

4, Cross-sections always isolated, rounded, various shapes, 
mostly kidney- shaped; with iodin and sulphuric acid, blue or 
violet; lumen contracted, hne- shaped, often containing a yel- 
lowish marrow; no stratification. 

Longitudinal appearance: fibres always separate; with 
iodine and sulphuric acid, a fine blue; streaked and twisted; 
lumen broad, distinct, frequently contains yellowish marrow; 
ends blunt; the entire fibre not soluble in concentrated sulphuric 
acid; coated with a very thin cuticle; length 10 to 60 mm,, 
breadth 12 to 42 /^ Cotton (see Fig. 55). 

II. Cross-section blue or violet with iodin and sulphuric 
acid; polyhedral, rounded or irregular; always surrounded by a 
yellow median layer. 

I. Cross-sections always in groups, with angles more or less 
rounded off, lying very close to one another; all of them sur- 



234 THE TEXTILE FIBRES. 

rounded by a thin, yellowish median layer; the lumen is line- 
shaped, single or forked, often broad, with inturning edges, with- 
out marrow; good concentric stratification; the different strata 
being differently colored. 

Longitudinal appearance: with iodin and sulphuric acid^ 
blue, greenish, or dirty yellow; fibres irregular in thickness, fre- 
quently with appended portions of yellowish median layer; joints 
and transverse lines frequent; stripes very distinct; the lumen is 
not very apparent, but broader than linen; ends are broad, thick- 
walled, and blunt, often branched; length 5 to 55 mm., breadth 
16 to 50 /« Hemp (see Fig. 62). 

2. Cross-sections in large groups, lying very close together and 
touching; very similar to those of hemp; often crescent- shaped. 
Polygonal or oval, with lumen of varying size, frequently contain- 
ing yelloMdsh marrow; lumen usually not line- shaped, but irregu- 
lar; a broad yellow median layer always present, from which the 
blue inner strata are easily distinguished; stratification very dis- 
tinct, as with hemp. 

Longitudinal appearance: as with hemp, except in dimen- 
sions, which are: length 4 to 12 mm., breadth 25 to 50 jx. 

Sunn hemp (see Fig. 47). 

(h) Leaf fibres. (With vascular tissue; without jointed 
structure. Esparto and Pineapple fibre.) 

1. Cross-sections in large, compact, often crescent- shaped 
groups; very small; pale blue or violet with iodin and sulphuric 
acid; surrounded by a thick, shell- like network of median layer; 
rounded or polygonal; lumen like a point or streak; thick cut- 
tings appear greenish or even yellow; frequently bundles of 
vascular tissue with one or two rows of thick, yellow-colored fibres. 

Longitudinal appearance: Fibres slender, regular, very 
thick- walled, smooth; lumen often invisible, generally as a fine 
line; ends are tapered with needle- like points; color with iodin 
and sulphuric acid, blue, often but slightly pronounced; fre- 
quently present short, thick, stiff, completely lignified fibres 
from vascular tissue; length 5 mm., breadth 6 jj.. 

Pineapple fibre. 

2. Cross-sections in groups; with iodin and sulphuric acid, 



QU^LIT/lTiyE /tNALYSIS OF THE TEXTILE FIBRES. 235 




Fig. 62. — ^Hemp. (Hohnel.) 
«, epidermis of hemp; b, ends of fibres; c, cross-section; d, longitudinal view. 



236 



THE TEXTILE FIBRES. 



mostly blue, though also yellow; often with pronounced stratifi- 
cation; the outer strata frequently yellow, while the inner are 
blue; rounded or oval, seldom straight- sided; lumen like a point. 
Longitudinal appearance: the fibres are short; blue with 
iodin and sulphuric acid; thin, very firm, smooth, uniform in 
breadth; lumen yellow, line- shaped; ends are seldom pointed, 
mostly blunt or chiselled off, or forked; length 1.5 mm., breadth 
12 jx , Esparto (see Fig. 63). 




Fig. 63. — Esparto-grass. (Hohnel.) 
S, short schlerenchymous elements; /, cells; /, fibres; h, hairs; e, epidermal cells. 



B. Fibres which are Colored Yellow with Iodin and Sulphuric 
Acid. 

{a) Dicotyledonous fibres. (Without vascular bundles; 
lumen showing remarkable contractions. Including Jute, Abel- 



QUALlT/ITll^E ANALYSIS OF THE TEXTILE FIBRES. 237 

moscJms, Gambo hemp, Urena, and Manila hemp; the latter 
sometimes shows vascular tissue.) 

I. Cross- sections in groups; polygonal and straight- lined, 
with sharp angles; lumen round or oval, smooth, and without 
marrow; cross- sections with narrow median layers showing the 
same color as the inner strata with iodin and sulphuric acid; 
lengthwise appearance shows the lumen with contractions. 

1. Cross-sections polygonal, straight-lined; lumen, in general, 
large, round, or oval. 

Longitudinal appearance: fibres smooth, without joints or 
stripes; lumen distinctly visible; broad; with contractions; the 
ends always blunt and moderately thick; ends have wide lumen; 
length 1.5 to 5 mm., breadth 20 to 25 /x Jute (see Fig. 40). 

2. Cross-sections in general somewhat smaller than jute; sides 
straight, with sharp angles; lumen frequently like a point or 
line, oval, occasionally pointed; not so large as with jute. 

Longitudinal appearance: fibres quite even in thickness, 
smooth, with occasional joints or stripes; lumen narrow, irregu- 
lar in thickness, contractions frequent; the ends are broad, 
blunt, frequently thickened; length i to 1.6 mm., breadth 8 to 

20 ,« Pseudo-jute or Musk mallow of Ahelmoschus. 

II. Cross-sections in groups, lying close together; polygonal, 
with sharp lines and sharp or rounded angles; lumen without 
marrow; the median layer is broad, and with iodin and sul- 
phuric acid is colored perceptibly darker than the inner layer of 
cell- wall; the lumen in places is completely lacking. 

1 . Cross-sections more or less polygonal, with sharp or slightly 
rounded angles; the lumen is small, becoming broader and more 
oval as the section is more rounded; the median layer is broad, 
and is colored considerably darker than the cell-wall with iodin 
and sulphuric acid; stratification occasional and indistinct. 

Longitudinal appearance: the fibres vary much in thick- 
ness; lumen generally narrow, with decided contractions, and in 
some parts totally absent; the broader fibres often striped; ends 
are blunt and generally thickened; length 2 to 6 mm., breadth 
14 to 33 ,« Gambo hemp (see Fig. 48). 

2. Cross-sections always in groups; small, polygonal, with 



238 



THE TEXTILE FIBRES. 



sharp angles; lumen very small, appearing as a point or a short 
line. 

Longitudinal appearance: occasionally jointed or striped; 
lumen with decided contractions, in some places altogether lack-, 
ing; ends blunt and sometimes thickened; length i.i to 3.2 
mm., breadth 9 to 24 fi. 

Pseudo-jute from Urena sinuata (see Fig. 64). 




Fig. 64. — ^Pseudo-jute. (H5hnel.) 
I, longitudinal view; v, interruption of lumen; e, end with thick wall; q, cross- 
section; m, median layer; L, small lumen. 



(b) MoNOCOTYLEDONOUS PiBRES. (Occurring as vascular 
bundles together with bast; the lumen exhibits no contractions; 
in Manila hemp vascular bundles often lacking. Includes New 
Zealand flax, Manila hemp, Sansevieria or bowstring hemp, Pita 
hemp, and Yucca fibre.) 

I. Cross-sections generally rounded, occasionally polygonal;, 
the lumen is always rounded, without contractions longitudinally; 
median layer indistinct, or only as a narrow line; vascular tissue 
small in amount, or altogether lacking. 

I. Cross-sections small, generally rounded, lying loosely sepa- 



QUALIT/ITiyE /tN/l LYSIS OF THE TEXTILE FIBRES. 239 

rated; very rounded angles; lumen small, round or oval, without 
marrow. 

Longitudinal appearance: the fibres are stiff and thin; 
the lumen is small but very distinct, and uniform in width; the 
ends are pointed; no markings and no joints; length 5 to 15 mm., 
breadth 10 to 20 /< New Zealand -flax (see Fig. 49). 

2. Cross-sections polygonal, with rounded angles, in loosely 
adherent groups; lumen large and round, often containing yellow 
marrow. 

Longitudinal appearance: fibres uniform in diameter; 
walls thinner than those of New Zealand flax; lumen large and 
distinct; ends pointed or slightly rounded; silicious stegmata 
adhering to the fibre-bundles and to be found in the ash as bead- 
hke strings, insoluble in hydrochloric acid; length 3 to 12 mm., 
diameter 16 to 32 n .*. .Manila hemp (see Fig. 50). 

11. Cross- sections polygonal; lumen large and polygonal, 
with angles quite sharp ; median layer lacking or only in the form 
of a thin line. 

1. Cross-sections distinctly polygonal, often with blunt angles, 
lying compactly together; lumen large and polygonal, with sharp 
angles; no stratification in cell- wall. 

Longitudinal appearance: fibres thin and smooth; lumen 
large and distinct; ends pointed; length 1.5 to 6 mm., diameter 
15 to 26 ,« Sansevieria fibre. 

2. Cross-sections polygonal, not many sections to a group, but 
lying compactly together; angles slightly rounded; lumen not 
very large, polygonal, often having blunt angles; besides the 
bast fibre sections are to be noticed some vascular bundles in the 
form of large spirals. 

Longitudinal appearance: fibres uniform in diameter; 
lumen not very large, but uniform; no structure; ends pointed 
and sometimes blunt; length 1.3 to 3.7 mm., diameter 15 to 24 ix. 

Aloe hemp (see Fig. 51). 

3. Cross-sections polygonal, with straight lines; angles sharp, 
though sometimes blunt; sections He compactly together; lumen 
large and polygonal, though angles not so sharp. 

Longitudinal appearance: fibres stiff, and often xery wide 



240 



THE TEXTILE FIBRES. 



towards the middle; lumen large; ends broad, thickened, and 
often forked ; large, shining crystals to be found in the ash, which 
are derived from the chisel-shaped crystals of calcium oxalate 
chnging to the outside of the fibre ; these crystals are often \ mm. 
in length; length of fibre i to 4 mm., diameter 20 to 32 fi. 

Pita hemp (see Fig. 65). 




Fig. 65. — ^Pita Hemp {Agave americana). 
A, longitudinal section; B, cross-section; e, blunt ends. 

III. Cross-sections polygonal and small, sides straight, with 
very sharp angles; lumen small, usually as a point or line-shaped; 
sections lie compactly together and are surrounded by a thick, 
distinct median layer. 

I. Cross-sections as above. 
Longitudinal appearance: fibres very narrow; lumen also 
very narrow; longitudinal ridges frequent; ends usually sharp- 
pointed; length 0.5 to 6 mm., diameter 10 to 29 11. 

Yucca fibre (see Fig. 66). 



QU/iUT/iTIl^E /ANALYSIS OF THE TEXTILE FIBRES. 241 

C. Analytical Review of the Chief Vegetable Fibres. 

I. Those occurring as thick, fibrous bundles, also with vascu- 
lar tissue (monocotyledonous fibres) (sec 2). 

Vascular tissue absent; sections and fibres always single; 
round or kidney- shaped by being pressed together; fibres with a 
thin external cuticle insoluble in concentrated sulphuric acid, and 
not sweUing (vegetable hairs) (see 7). 




Fig. 66. — Yucca Fibre. 
A, longitudinal view; B, cross-section; m, median layer; t, transverse markings. 

Vascular tissue absent; the fibres are bundles of bast fila- 
ments; sections occurring two or more together (mostly true 
dicotyledonous fibres) (see 13). 

2. Lumen very narrow, line- shaped, much thinner than the 
wall ' (see 3). 

Lumen in thickest fibres almost as wide, or even wider, 
than the wall; completely hgnified (see 4). 

3. Sections polygonal, sides straight, with sharp angles; com- 
pletely Hgnified; diameter 10 to 20 /^. . . Yucca fibre (see Fig. 66). 

Sections rounded to polygonal; often flattened or egg- 
shaped ; the inner strata at least not lignified ; diameter 4 to 8 /u 

Pineapple fibre. 

4. Thick, strongly silicified stegmata occurring at intervals on 
the fibre-bundles in short to long rows, sometimes but few; these 
are four-cornered, have serrated edges, and show a round, bright, 
transparent place in the middle; they are easily seen after the 
fibre has been macerated with chromic acid, and are about 30 /j. 
in length; in the ash of fibres previously treated with nitric acid, 



242 THE TEXTILE FIBRES. 

they appear in the form of pearly strings, often quite long, and 
insoluble in hydrochloric acid; they are joined together length- 
wise; the fibres are thick- walled, with fissure-like pores; 3 to 
12 mm. long; the fibre-bundles are yellowish and lustrous. 

Manila hemp (see Fig. 48). 

Stegmata present, sometimes in small, sometimes in large 
quantities; they are lens- shaped, small (about 15 ;< wide), and are 
fastened to the exterior fibres of the bundles by serrated edges; 
in the ash of the fibre they melt together in the form of indistinct 
globules; in the ash of fibres previously boiled in nitric acid they 
appear as yeast-cells, joined together in round skeletons of silica; 
the fibres are often thin- walled, with numerous pores; i to 2 mm. 
in length ; the raw fibres generally brown and rough Coir. 

Stegmata absent, hence the fibres are not accompanied by 
silicified elements (see 5) . 

5. Fibre-bundles covered externally at intervals with crystals 
of calcium oxalate, at times up to 0.5 mm. in length; lustrous, 
with quadrangular sections, chisel-shaped at the ends, hence they 
appear as thick, needle-shaped crystals; when present in large 
numbers these crystals occur in long rows which are frequently 
visible to the naked eye, and always easily recognizable under the 
microscope, especially in the ash. The fibre-bundles are mostly 
thick, and their outer fibres (as a result of their preparation) fre- 
quently contain fissures or are torn; thickness of the walls very 
uneven; fibres often much widened at the middle. 

Pita hemp (see Fig. 65). 

Without crystals, generally thin; in cross- section usually 

less than 100 fibres to a bundle; thickness of walls and lumen 

very uniform (see 6). 

6. Sections mostly round, not very compact; lumen usually 
thinner than the waU, but never a single Hne; in section round or 
oval; vascular tissue in but small amount. 

New Zealand -flax (see Fig. 49). 

Sections, on one side at least, polygonal; section of lumen 

polygonal, with angles more or less sharp; generally as wide or 

wider than the wall; vascular tissue frequent. 

' Aloe hemp (see Fig. 51). 



QUALITATIVE ANALYSIS OF THE TEXTILE FIBRES. 243 

7. Fibres mostly rope- shaped, twisted, externally streaked, 
generally possessing fine granules or marked with Httle lines, 
therefore rough; thin to thick walls; cross- sections squeezed 
together, or round to kidney- shaped, hence the fibre has more or 
less the shape of a flat band; section of lumen more or less 
arched, line- shaped, frequently containing yellow marrow; con- 
sists of pure cellulose with the exception of the thin cuticle. 

Cotton (see Fig. 55). 
Fibres not twisted, smooth externally, and without longi- 
tudinal markings; fibres not flat, sections round;, walls generally 
ver}' thin; sometimes, however, they are thick; lignified, scarcely 
swelHng in ammoniacal copper oxide. . . . Vegetable down | 

Vegetable silks ) '' 

8. Fibres on the inside possess from 2 to 5 broad ridges, which 
at times are very noticeable, at others scarcely visible; they run 
lengthwise in the fibre, and in section are semicircular; on this 
account the walls appear unequal in thickness when viewed 
longitudinally; the maximum thickness is about 35 {i. 

Vegetable silks (see 9) . 

Fibres without ridges; maximum thickness mostly 30 to 

35 11 Vegetable down (see 12). 

9. Largest diameters 50 to 60 //; length 3.5 to 4.5 cm. . (see 10). 
Largest diameters 35 to 45 ^; length 1.5 to 4 cm. . (see 11). 

10. Fibres contracted at the lower end, and directly above 
abruptly swelling, becoming 80 [x thick; the under portion of the 
swollen area contains numerous pore-canals; fibres feather-like 
or brush-like, arising from a straight shaft. 

Vegetable silk from Senegal. 
Contrary to the above the fibres originate from one point, 
like a fan; remarkably strong, curved backwards; very firm. 

Vegetable silk from India. 

Like the foregoing, but the fibre is stiff, straight, weak, 

and brittle Calotropis procera. 

11. Thickened ridges very noticeable; in the cross- sections 
often occurring in the form of a semicircle; bound together in a 
strictly reticulated manner. 

Vegetable silk from Asclepias cornutii. 



244 



THE TEXTILE FIBRES. 



Thickened ridges indistinct, projecting but slightly in 
the cross-section Vegetable silk from Asclepias curassavica. 

12. Raw fibre, yellowish; broadened at the lower end (up to 
50 11) ; also reticular thickening or transverse markings ; wall i to 
2 II thick Bombax cotton (Fig. 59) 

Raw fibre, brown; the lower end contracted and not show- 
ing reticulated thickenings; fibre almost altogether thin- walled, 
though just at the lower end very thick-walled. 

Cochlospernum gossypium. 

13. Thick fibre-bundles, whose outer surface contains at inter- 
vals series of thick sihcious plates, having sharp indented edges 
and a round, hollow space Manila hemp (see under 4). 

Sihcious plates absent; lengthwise the lumen often exhibits 
remarkable contractions, while the wall is very uneven in thick- 
ness; at intervals, indeed, the lumen is almost entirely inter 
rupted; joints and transverse fissures along the fibre; transverse 
markings and lines, which appear somewhat like zones or knots, 
are completely lacking, or are very rare and indistinct; com- 
pletely hgnified, hence colored yellow with iodin and sulphuric 
acid (see 14). 

Sihcious plates absent, also remarkable contractions of 
the lumen; thickness of the walls very uniform; joints and fissures 
along the fibre, transverse lines and markings frequent, hence 
the fibre often appears as if it contains swollen knots; unhgni- 
fied, or only lignified on the external layer of membrane, hence 
lengthwise the fibre is colored blue with iodin and sulphuric acid 
or violet or green, or at the most colored yellow in places . . (see 17). 

14. Exterior layers of membrane narrow and showing the 
same coloration with iodin and sulphuric acid as the inner layers, 
hence the same as the entire cross-section; the lumen hardly 
ever completely interrupted '. (see 15). 

Median layer in sections wide; colored considerably 
darker with iodin and sulphuric acid; lumen often completely 
interrupted (see 16). 

15. Lumen in general large, diameter as wide or only a httle 
narrower than the wall; in section round or oval, seldom as a 
point; no crystals of calcium oxalate.. . . True jute (see Fig. 40). 



QUALITATII^E ANALYSIS OF THE TEXTILE FIBRES. 245 

Lumen usually small, diameter much narrower than the 
thick wall in section frequently as a point; crystals of calcium 
oxalate of frequent occurrence (detected by ignition). 

Pseudo-jute (Abelmoschus) (see Fig. 67). 




Fig. 67. — Ahelmoschus Jute. (Hohnel.) 

/, longitudinal view; q, cross-section; e, ends; L, small lumen; v, narrowing of 

lumen. 



16. Lumen almost always considerably smaller than the wall; 
ends usually very thick- walled and narrow, calcium oxalate crj's- 
tals of frequent occurrence. 

Pseudo-jute {Urena sinuata) (see Fig. 64). 

Lumen frequently as wide as or wider than the wall, mostly 

narrower however; ends broad and blunt . Gambo hemp (see Fig. 48). 

17. The lumen in the middle portion of the fibre generally 
line-shaped, much narrower than the wall; ends never blunt, 
always sharply pointed; sections isolated or in small groups, 
regular in diameter, sharp-angled and straight-sided polygonals; 



246 



THE TEXTILE FIBRES. 



without separate median layer; iodin and sulphuric acid colors 
the entire section blue or violet; the lumen in the cross- section is 
very small, or as a point, containing a marrow which is colored 
yellow with iodin and sulphuric acid. .Linen or Flax (see Fig. 68). 




Fig. 68. — ^Linen Fibre. 
Showing jointed structure or knot-like formation at /. 

Lumen, at least in the central portion of the fibre, always 
much thicker than the walls; in section generally more or less 
flattened, narrow to broad, egg-shaped or oval. Fibre ends 
blunt, never sharply pointed; sections almost never sharp-angled 
polygonals, but more or less oval or elliptical, and with a rounded 
boundary (see 18). 

18. Breadth of fibre up to 80 /i; maximum length 15 to 60 mm. ; 
sections always in compact groups, which often consist of many 
fibres, with thinner or thicker layers of membrane which are col- 
ored yellow with iodin and sulphuric acid, hence the fibre is 
never colored a pure blue, but dirty blue to greenish, and in places 
yellow; ends often have side branches projecting (see 19). 

19. Lignified exterior membranes very thin; lumen in sec- 
tion narrow, very seldom broad, fissure-like or hne-shaped, often 
branched, without marrow Hemp (see Fig. 62). 

Lignified exterior layers often as wide as the interior layers, 
or wider; the interior layers are often loosened in places from the 
exterior ones where they are thin; lumen in section scarcely ever 
narrow or fissure-shaped, but broad, oval, or long; often contain- 
ing a yellowish marrow Sunn hemp (see Fig. 47). 



CHAPTER XVII. 

QUANTITATIVE ANALYSIS OF THE TEXTILE FIBRES. 

I. Wool and Cotton Fabrics. — The finishing materials and 
coloring-matters should be removed as far as possible by boiling 
the sample to be examined first in a i per cent, solution of hydro- 
chloric acid, then in a dilute solution of sodium carbonate (about a 
one-twentieth per cent, solution), and finally in water. A por- 
tion of the material is then dried at ioo° C. for an hour (or until 
constant weight is obtained) and weighed; this weight will repre- 
sent the actual amount of true fibre present in the sample, and 
the loss will correspond to moisture. Then steep for twelve hours 
in a 20 per cent, solution of sulphuric acid, and mix with three 
volumes of alcohol and water; filter off the dissolved cotton and 
wash the residue of wool well with alcohol. Dry at 100° C, and 
weigh; this will give the amount of wool present. The following 
example will illustrate this method: 

Grams. 

Sample weighed 3-62 

After treatment with acid and alkali 3-i7 

Finishing materials, etc o • 45 

After drying at ioo° C 2.77 

Loss as water o . 40 

Wool left after treating with acid i . 96 

Cotton, by difference 0.81 

Hence the composition of this sample would be as follows: 

Per Cent. 

Finishing materials 12 . 43 

Moisture 1 1 • 05 

Wool 54-14 

Cotton 22 . 38 

100.00 

247 



248 THE TEXTILE FIBRES. 

Another, and perhaps a better, method for determining the 
relative amounts of wool and cotton in a mixed fabric or yarn, 
especially when the cotton is present in rather large proportion, 
is to remove the wool by treatment with a dilute boiling solution 
of caustic potash. The estimation is carried out in the following 
manner : 

The sample to be tested is treated with hydrochloric acid and 
sodium carbonate solutions as before, in order to remove finish- 
ing materials, and after thorough washing is dried at 100° C. and 
weighed. This gives the weight of the dry fibres. The weighed 
sample is then boiled for twenty minutes in a 5 per cent, solution 
of caustic potash.* The residue is well washed in fresh water, 
and redried at 100° C. and weighed. The residue consists of 
cotton, the wool having been dissolved by the caustic potash.f 
If the residue becomes disintegrated and cannot be washed and 
dried as one piece, it should be collected on a tared filter (one 
which has been dried at 100° C. and weighed) and well washed 
with water, then dried at 100° C. and weighed. The tared weight 
of the filter subtracted from the latter will give the weight of the 
cotton particles. 

Examples : 

(a) Analysis of a cloth sample: 

Grams. 

Weight of sample 5-42 

After treatment with acid and alkali 5 ■ lo 

Finishing materials, etc 0.32 

After drying at 100° C 4.26 

Loss as water o. 84 

Cotton left after boiling with caustic alkali 2.82 

Wool, by difference i ■ 44 

* It is not advisable to use caustic soda instead of caustic potash, as the results 
obtained are not as satisfactory. 

t In case yarns are to be analyzed, the preliminary treatment should consist 
of a thorough scouring with soap. After drying in the air, the loss in weight should 
be recorded as grease and miscellaneous dirt. On then drying at 100° C. to con- 
stant weight, the loss will represent moisture, and the residue dry fibre. This 
is then analyzed as in the manner above described. 



QUyiNTIT/ITiyE AN/iLYSIS OF THE TEXTILE FIBRES. 249 
Hence the composition of this sample would be : 

Per Cent. 
Finishing materials 5-98 

Moisture 15 • 5° 

Cotton 52 • 03 

Wool 26 . 49 



100.00 

Since the cotton itself suffers a sHght loss on boiling with 
caustic potash, it is customary, as a correction, to add to the cotton 
found 5 per cent, of its weight, and to subtract a corresponding 
amount from that of the wool. On applying this correction the 
result of the above analysis would become: 

Per Cent. 
Finishing materials 5 • 98 



Moisture 15 

Cotton 54 

Wool 23 



Figured on the weight of the dry fibre, the relative amounts of 
the two fibres in the above samples would be: 

Per Cent. 
Cotton 69 . 5 

Wool 30.5 

100.00 
Since, however, in making mixes, the dry weights of the fibres 
are not taken, we may assume the weight to include the normal 
amount of moisture held by each fibre. As the normal amount 
of moisture for cotton is about 8 per cent., and for wool about 
16 per cent., we may approximate very closely to the true compo- 
sition of this sample by adding to the dry weights of the fibres their 
respective amounts of moisture; the relative amounts of cotton 
and wool then become: 

Grams. 
Weight of cotton found 2.82 

Add 5 per cent, correction o. 14 

2.96 
This represents 92 per cent, of air-dry cotton. 

Hence air-dry cotton would be 3-22 

Weight of wool found i • 44 

Subtract correction for cotton o. 14 

1.30 



250 THE TEXTILE FIBRES. 

This represents 84 per cent, of air-dry wool. 

HcHce air-dry wool would be i • 54 

Therefore the relative amounts of cotton and wool on this 
basis would be : 

Per Cent. 
Cotton 65 .8 

Wool 34 . 2 

{h) Analysis of a yarn : 

Grams. 
Weight of sample 5-65 

Scoured in soap, washed, and air-dried 4-97 

Grease, etc o. 68 

Dried at 100° C 4-32 

Loss as moisture 0-65 

Weight of filter-paper dried at 100° C 1.16 

Weight of filter and residue of cotton dried at 

100° C 3 . 66 

Weight of dry cotton. 2 . 50 

Add 5 per cent, correction 2 . 62 

Correct for moisture at 8 per cent 2 . 85 

Weight of dry wool by difference (with correction) . i . 70 
Correct for moisture at 16 per cent 2 .02 

Hence the composition of this yarn may be expressed as: 

Per Cent. 
Grease, etc 1 2 . 00 

Moisture ii-5o 

Cotton. 44-25 

Wool 32 . 25 



And the relative proportion of the two fibres would be as 
follows : 

Dry at 100° C. Air-dry. 

Cotton 60 . 7 58.5 

Wool. 39 . 3 41-5 



100.00 

When a rough, approximate analysis of a wool- cotton is 
desired, it will be sufficient only to weigh the sample, boil for 
fifteen minutes in a 5 per cent, solution of caustic potash, wash 
well in acidulated water, then in fresh water, and dry in the air. 
On reweighing, the amount of cotton will be ascertained, while 



QUANTITATIVE ANALYSIS OF THE TEXTILE FIBRES. 251 

the loss in weight will represent the amount of wool. Results 
attained by this process are usually sufficiently accurate to give 
one a practical idea of the approximate relative amounts of wool 
and cotton present in a sample of mixed goods. 

Another method for the separation of wool from cotton in 
their quantitative estimation is treatment of the mixed fibre? 
with an ammoniacal solution of copper oxide, whereby the cotton 
is dissolved; and after washing and drying, the residue of wool is 
weighed. This method, however, is not very satisfactory, as it 
is difficult, in the first place, to obtain a complete and thorough 
solution of the cotton; and in the second place, the wool will be 
considerably affected by this treatment and more or less decom- 
posed. Consequently the results obtained by this method are 
not very accurate, and it cannot be recommended. 

2. ■Wool and Silk. — Silk is soluble in boiling hydrochloric 
acid, whereas wool is not soluble in this reagent to any extent. 
Hence this method may be utilized for the quantitative estima- 
tion of the two fibres when occurring together. The sample is 
first treated with acid and alkali in the manner already described 
in order to remove foreign materials other than actual fibre. It 
is then dried and weighed; then boiled in concentrated hydro- 
chloric acid for fifteen minutes. The residue is collected, washed 
thoroughly, dried again, and weighed. The loss in weight repre- 
sents silk, while the weight of the residue represents wool. An- 
other method, and one which is perhaps more satisfactory, is 
to dissolve the silk by treatment with an ammoniacal solution of 
nickel oxide, in which reagent the silk is very readily soluble 
€ven in the cold. It only requires a treatment of about two min- 
utes to completely dissolve the silk in most silk fabrics other than 
plush. Richardson * found that by this treatment cotton lost 
only 0.45 per cent, in -weight and wool only 0.33 per cent. As 
silk in plush goods and similar fabrics is much more difficult to 
dissolve, it is recommended to boil such material with the nickel 
solution for ten minutes under a reflux condenser. By this treat- 
ment cotton will lose only 0.8 per cent, in weight. The nickel 
solution is best prepared by dissolving 25 grams of crystallized 

* Jour. Soc. Chem. Ind., xil. 430. 



252 THE TEXTILE FIBRES. 

nickel sulphate in 80 c.c. of water; add 36 c.c. of a 20 per cent, 
solution of caustic soda, carefully neutralizing any excess of alkali 
with dilute sulphuric acid. The precipitate of nickel hydroxide 
is then dissolved in 125 c.c. of strong ammonia, and the solution 
diluted to 250 c.c. with water. Instead of the above reagent, a 
boiling solution of basic zinc chloride may be employed for the 
purpose of dissolving the silk. This latter solution is obtained by 
heating together 1000 parts of zinc chloride, 850 parts of water, and 
40 parts of zinc oxide until complete solution is effected. Rich- 
ardson recommends that the sample to be examined should be 
plunged two or three times into the boiling solution of zinc chloride, 
care being taken that the total time of immersion does not exceed 
one minute. The zinc chloride solution should be sufficiently 
basic and concentrated in order to obtain good results. Under 
the best conditions, cotton loses about 0.5 per cent, in weight, and 
wool from 1.5 to 2.0 per cent. 

3. Silk and Cotton. — The methods given above for separating 
silk from wool may also be used for the separation and quantita- 
tive determination of silk in fabrics containing this fibre in con- 
junction with cotton. 

Another method for separating silk from cotton is by the use 
of an alkaline solution of copper and glycerin, which serves as an 
excellent solvent for the silk. The reagent is prepared as follows: 
Dissolve 16 grams of copper sulphate in 150 c.c. of water, with 
the addition of 10 grams of glycerin; then gradually add a solution 
of caustic soda until the precipitate of copper hydrate which is 
at first formed just redissolves. This solution readily dissolves 
silk, but is said not to affect either wool or the vegetable fibres. 
Richardson, however, has found that cotton heated with this 
solution for twenty minutes (the time necessary to dissolve silk in 
plush) lost from i to 1.5 per cent, in weight and became friable 
and dusty on drying; while woolen fabrics lost from 9 to 16 per 
cent, in weight. Hence the reagent would be useless in the analy- 
sis of fabrics containing wool. 

4. Wool, Cotton, and Silk. — Samples of shoddy frequently 
contain all three of these fibres present in greater or lesser 
amount, and. often it is desirable to know at least the approx- 



QU/INTIT/tTIVE ANALYSIS OF THE TEXTILE FIBRES. 253 

imate amounts of each fibre in the mixture. A method of pro- 
cedure recommended is the following: A weighed sample of the 
material is boiled for thirty minutes in a 3 per cent, solution of 
hydrochloric acid, washed, and then boiled for thirty minutes in a 
0.1 per cent, solution of soda-ash. This preliminary operation is 
similar to that above described in the preceding analyses, and is 
for the purpose of freeing the fibres as far as possible from extra- 
neous foreign matter. After thorough washing and air-drying, 
the weight of the sample is again taken, and the loss will represent 
miscellaneous foreign matter. The sample is then dried at 100° C. 
to constant weight; the loss in weight will represent moisture. 
The sample is then divided into two weighed portions; the first 
is treated for five minutes with a boiling solution of basic zinc 
chloride prepared as above described, washed thoroughly with 
acidulated water, then with fresh water, and dried at 100° C. 
again. The loss in weight will represent the amount of silk 
present. The second portion of the sample is boiled for ten min- 
utes in a 5 per cent, solution of caustic potash; washed thor- 
oughly, dried at 100° C. and weighed. This weight, with a cor- 
rection of 5 per cent, added to it, will represent the amount of 
cotton present. The amount of wool is obtained by taking the 
difi^erence between the total weight of the combined fibres and 
the sum of the weights of the silk and cotton. 
Example: 

Grams. 
Sample of loose shoddy weighed 5 • 06 

Treated with acid and alkali, and air-dried 4. 23 

Loss as foreign matter 0-83 

Dried at 100° C 3 . 62 

Loss as moisture 0.61 

Divided into two portions: 

Grams. 
(a) weighed i ■ 95 

(6) weighed i . 67 

(a) treated with zinc chloride i • 73 

Loss as silk 0.22 

ip) treated with caustic potash, residue as cotton.. . . c.34 
Loss as wool "^ -3,2, 



2 54 THE TEXTILE FIBRES. 

Hence the composition of this sample on the basis of dry 
fibre would be: 

Per Cent. 

Silk II. 3 

Cotton 21.5 

Wool 67 . 2 

100. o 

Von Remont gives the following method for analyzing fabrics 
containing a mixture of silk, wool, and cotton. Four quantities 
{A, B, C, D) of 2 grams each of the air-dried material are weighed 
out. Portion A is kept aside, and each of the other three is 
boiled for fifteen minutes in 200 c.c. of water containing 3 per 
cent, of hydrochloric acid. The liquid is decanted, and the 
boiling repeated with more dilute acid. This treatment removes 
the size and the major portion of the coloring-matter. Cotton is 
nearly always decolorized quite rapidly, wool not so readily, and 
silk but imperfectly, especially with black-dyed fabrics. The 
samples should be well washed and squeezed in order to remove 
the acid liquor. Portion B is set aside. Portions C and D are 
then placed for two minutes in a boiling solution of basic zinc 
chloride (of 1.72 sp. gr., and prepared as above described), which 
dissolves any silk present. They are then washed with water 
containing i per cent, of hydrochloric acid, and again with pure 
water, until the washings no longer show the presence of zinc. 
Portion C is squeezed and set aside. Portion D is boiled gently 
for fifteen minutes with 60-80 c.c. of caustic soda solution (1.02 
sp. gr.) in order to remove any wool. The sample is then care- 
fully washed with water. The four portions are next dried for 
an hour at 100° C, and then left exposed to the air for ten hours 
in order to allow them to absorb the normal amount of hygro- 
scopic moisture. The four samples are then weighed, and call- 
ing a, b, c, and d their respective weights, we shall have 

a — b = dye and finishing material; 
Z> — c = silk; 
c — d = wool; 

(^ = cotton (or vegetable fibre). 

This method is open to objections, as the plan of using air- 



QUANTIT/mVE ANALYSIS OF THE TEXTILE FIBRES. 255 

dried material, then drying at 100° C, and subsequently expos- 
ing to the air again before reweighing, is liable to give very errone- 
ous results. Richardson recommends that the samples should 
be thoroughly dried at 100° C. before being weighed out, and 
the treated portions should subsequently be dried at the same 
temperature before weighing. In order to prevent the sample 
from absorbing moisture during weighing, it is best to use a weigh- 
ing-bottle for holding the dried fibre. The sample before dry- 
ing is placed in a weighing- bottle (the weight of which has been 
ascertained previously) and heated in an air-oven at 100° C. for 
the time specified, during which the cover of the weighing-bottle 
is removed. After the drying process is completed the stopper 
is replaced in the weighing-bottle; the latter is taken from the 
oven, allowed to cool, and is then weighed. The difference 
between this weight and the weight of the empty bottle will give 
the amount of dry fibre. 

Treatment with a boiling solution of 3 per cent, hydrochloric 
acid for the purpose of removing finishing materials is rather too 
severe, as the acid will act on the wool and the cotton, some- 
times causing considerable error. BoiHng with a i per cent, 
solution of acid for ten minutes is to be preferred. 

The following is given as a practical method to determine if 
shoddy contains cotton and silk fibres : Boil 10 grams of the shoddy 
to be tested for one hour in 400 c.c. of water containing 0.8 gram 
of alum, 0.3 gram of tartar, i c.c. of hydrochloric acid, o.i gram of 
chrome, and 0.05 gram of blue-stone. Rinse and dye with 0.3 
gram of logwood extract. Rinse and dry. The undyed fibres are 
then picked out and examined; cotton will remain white, while 
silk will be colored a dingy red. 

The analysis of heavy pile fabrics containing a mixture of 
fibres is especially difficult unless the fabric is disintegrated. In 
the analysis of plush for the amount of silk present, Richardson 
suggests treating the sample with a boiling solution of basic zinc 
chloride in the manner previously described; but when silk is to 
be determined in hght fabrics (especially in the presence of wool), 
it is best to treat the sample for one to three minutes with a cold 
solution of ammoniacal ni':kel oxide. He gives the following 



256 



THE TEXTILE FIBRES. 



comparison of results in the analysis of a sample of plush, using 
the three different methods for dissolving the silk: 



By Solution 
of Ammoniacal 
Nickel Oxide. 



By Solution 

of Basic 

Zinc Chloride. 



By Copper- 
glycerin 
Reagent. 



Moisture and finish 

Silk 

Cotton 



11-34 
45.60 
43.60 



II .00 
45.00 
44.00 



10.04 
47.06 
42.90 



Samples of plush with hard cotton backs may best be analyzed 
by successive treatment with acid and copper-glycerin reagent. 
On other cotton material, however, this method is not suitable; 
nor is it to be used in the presence of wool, as this fibre is consid- 
erably dissolved by the copper-glycerin reagent. 

The following table by Richardson shows a comparison of 
the three methods employed for dissolving silk : 





Actually 
Present. 


Percentage Obtained by 


Fibre. 


Ammoniacal 
Nickel Oxide. 


Basic Zinc 
Chloride. 


Copper-glycerin 
Reagent. 


Silk 


5-84 
76-31 
17-85 


5-92 
76.58 

17-50 


5-52 
80.08 
14.40 


18.80 


"Wool 


64.05 


Cotton 


17-15 







The ammoniacal nickel oxide solution appears to give the best 
result; hence in analyzing a sample containing silk, wool, and 
cotton, it is best to first remove the silk by means of this reagent. 
The insoluble residue left after this treatment is boiled with a 
I per cent, solution of hydrochloric acid, washed well in fresh 
water, and then boiled for five to ten minutes in a 2 per cent, 
solution of caustic soda, which is sufficient to completely remove 
the wool without materially affecting the cotton. 

Allen * also recommends the ammoniacal nickel solution for 
use in dissolving silk from a mixture of fibres. His method of 
analyzing a textile sample is as follows: The yarn or fabric is cut 



* Commer. Org. Anal., vol. iv. 523. 



QUANTITATiyE ANALYSIS OF THE TEXTILE FIBRES. 257 

up very fine with a pair of scissors, and thoroughly dried at 100° C. 
One gram of the material thus prepared is treated with 40 c.c. of 
the cold ammoniacal nickel oxide solution for two minutes. The 
liquid is then filtered, and the residue, consisting of wool and 
cotton, is digested for two or three minutes in a boiling solution 
of I per cent, hydrochloric acid. It is then washed free from 
acid, dried at 100° C, and weighed. To separate the wool from 
the cotton the residue is boiled with about 50 c.c. of a i per cent, 
solution of caustic potash for ten minutes, and the solution fil- 
tered. The residue, consisting of cotton, is washed free from 
alkali, dried at 100° C, and weighed. 

To remove gum and weighting materials from goods contain- 
ing silk, Richardson recommends treatment of the sample with a 
cold 2 per cent, solution of caustic potash; this not only removes 
any gum, but also decomposes any Prussian blue that may be 
present (as a bottom under the black dye), so that the iron may 
be more easily removed by subsequent treatment with a i per cent, 
solution of hydrochloric acid. Metallic mordants, however, are 
difficult to remove in this manner, and at best they dissolve only 
imperfectly; it is best to calculate their amounts from the quan- 
tity of ash left after the ignition of the sample. 

Oily matter (and also certain dyes) may be best removed 
by boihng successively with methylated spirits and ether. By 
evaporation of the solution so obtained the amount of oil and fat 
may be directly determined. 

Hohnel recommends the use of a semi-saturated solution of 
chromic acid (see p. 217) for the quantitative separation of mix- 
tures containing wool, cotton, flax, true silk, and tussah silk. 
On boiling such a mixture of fibres in this solution for one min- 
ute, the wool and true silk will be completely dissolved, leaving 
as a residue the cotton, flax, and tussah silk. 

Other methods given by Hohnel for the quantitative analysis 
of fabrics containing mixtures of the fibres mentioned above are 
as follows: 

(a) Any true silk is first removed by boihng for half a minute 
in concentrated hydrochloric acid; tussah silk is next removed 
by a longer boihng in the acid (three minutes); the residue, con- 



25 8 THE TEXTILE FIBRES. 

sisting of wool and vegetable fibres, is further separated in the 
usual manner by boiling in caustic potash solution. 

(&) The fabric is first boiled in caustic potash solution, which 
dissolves the wool and the true silk, and leaves as a residue {A) 
tussah silk and vegetable fibre. A second sample is boiled for 
three minutes with concentrated hydrochloric acid, which dis- 
solves both varieties of silk and leaves as a residue {B) wool and 
vegetable fibre. Residue A is then boiled three minutes with 
concentrated hydrochloric acid, which dissolves the tussah silk 
and leaves the cotton as a final residue. By subtracting this 
amount from residue B the amount of wool is obtained. 

(c) A sample of the fabric is boiled for one minute in a semi- 
saturated solution of chromic acid, which dissolves the true silk 
and the wool, leaving as a residue the tussah silk and vegetable 
fibre. From this residue the tussah silk is removed by boiling 
for three minutes in concentrated hydrochloric acid, leaving the 
vegetable fibre as a final residue. A second sample is boiled for 
three minutes in concentrated hydrochloric acid, which dissolves 
the silks and leaves the wool and vegetable fibre as a residue. 
From this the amount of wool can be obtained either by boihng 
in caustic potash solution, or by subtracting the cotton previ- 
ously estimated. Finally, the amount of true silk may be found 
by subtracting the sum of the other constituents from the total in 
the original sample. 

5. Analysis of Weighting in Silk Fabrics. — ^The practice of 
adding to the weight of silk in the dyeing and finishing operations 
has become so common that it is frequently desirable to ascer- 
tain in a sample of silk goods the amount of true fibre present 
and the amount and character of weighting. Black-dyed silk 
is especially liable to contain a very large amount of weighting 
materials; sometimes the degree of weighting may reach as high 
as 400 per cent., or even more. Colored silks are usually not 
weighted to such a great extent, but they will frequently be found 
to also contain considerable adulteration. Black-dyed silks are 
mostly loaded with Prussian blue and iron tannate, the latter 
being obtained by immersing the silk in a solution of pyrolignite 
or nitrate of iron, and subsequently in a solution of cutch or other 



QUANTITATIVE ANALYSIS OF THE TEXTILE FIBRES. 25^ 

tannin. Colored silks are principally weighted with tin phos- 
phate obtained by treating the material with solutions of tin per- 
chloride and sodium phosphate. Sometimes light colored silks 
are also weighted with sugar, magnesium chloride, etc. Such 
materials are soluble in warm water, and hence their use is easily 
detected. 

A convenient test which is frequently applicable to detect 
weighting is, to ignite the silk fibre ; if it is heavily weighted it will 
not inflame, but gradually smoulder away and leave a coherent 
ash retaining the original form of the fibre. 

In general the substances which may be present as weighting 
materials are iron, as ferrocyanide or tannate; tin, as tannate, 
tungstate, phosphate, silicate, or hydroxide; chromium com- 
pounds; the sulphates or chlorides of sodium, magnesium, and 
barium; organic matters, such as sugar, glucose, gelatin, tannins, 
etc. 

The following method for the qualitative analysis of weight- 
ing materials on silk has been recommended by Silbermann : * 
Substances that are easily soluble, such as sugar, glucose, gly- 
cerin, magnesium salts, etc., are estimated directly by boiling 
the silk with water, and testing the extract with Fehling's solution, 
etc.f From 2 to 3 grams of the silk are ignited and the ash is 
tested for tin (which may be present in the fibre as basic chloride 

* Chem. Zeit., xviii. 744. 

t Fehling's reagent is an alkaline solution of copper sulphate containing potassium 
tartrate. It is prepared in the following manner: 34.639 grams of pure crystallized 
copper sulphate are dissolved in about 250 c.c. of water; 173 grams of Rochelle 
salt (sodium potassium tartrate) are dissolved in the same quantity of water; 60 
grams of caustic soda are similarly dissolved. The three solutions are then mixed, 
and the mixture diluted to 1000 c.c. with water. The reagent is employed as 
follows: 10 c.c. of the solution are diluted with 40 c.c. of water and brought to 
a boil; there is then added a portion of the solution to be tested for sugar (or glu- 
cose) which has previously been boiled with a small quantity of dilute hydro- 
chloric acid. If sugar is present, the Fehling's solution will be decolorized and 
a bright red precipitate of cuprous oxide will be thrown down. This test may 
be made quantitative by using a known quantity of sugar solution, filtering off the 
cuprous oxide, igniting, and finally weighing as copper oxide (CuO). In order 
to determine the amount of sugar (or glucose) corresponding to this latter, refer- 
ence should be made to tables constructed by .\llihn showing the proper equiva- 
lents of sugar and glucose for the amounts of copper oxide determined. 



26o THE TEXTILE FIBRES. 

and stannic acid), chromium, iron, etc.* Fatty matters, wax, 
and paraffin are detected by extraction with ether or benzene, f 
The silk is soaked in warm dilute hydrochloric acid (i : 2) ; if 
the fibre is almost decolorized by this treatment, only a slight 
yellow tint remaining, whilst the solution assumes a deep brown- 

* These metals may be tested for in the ash in the following manner: Moisten 
with a few drops of nitric acid and re-ignite in order to be certain that all carbon 
is removed. Treat the residue with eight to ten drops of strong sulphuric acid, 
and gently heat until fumes are evolved; allow to cool and boil with water; 
dilute to about loo c.c. with water, and then pass hydrogen sulphide gas 
through the liquid; filter, and examine the solution and precipitate as follows: 
The aqueous solution may contain zinc or iron; add a few drops of bromin- 
water to remove excess of hydrogen sulphide, and to oxidize any iron present 
to the ferric condition; boil, then add ammonia in slight excess; boil again, 
and filter; if there is a precipitate, it may contain iron; if so, it should be 
brown in color; dissolve in a little hydrochloric acid and add a few drops 
of a solution of potassium f errocyanide ; a blue color will confirm the presence 
of iron. The filtrate, which may contain zinc, should be heated to the boil, 
and a few drops of potassium f errocyanide solution added; a white precipitate 
will indicate zinc. The original precipitate produced by the treatment with 
hydrogen sulphide is next examined. This may contain lead, tin, or copper; 
it is fused for ten minutes in a porcelain crucible with 2 grams of a mixture of 
potash and soda ash together with i gram of sulphur. On cooling, the mass 
is boiled with water and filtered. The residue may contain lead and copper; 
it is boiled with strong hydrochloric acid, and a few drops of bromin-water are 
added for the purpose of completely oxidizing any copper sulphide present; filter 
if necessary, and add to the filtrate an excess of ammonia, when a blue color will 
indicate presence of copper. Acidulate the liquid with acetic acid and divide 
into two portions: to the first add a few drops of a solution of potassium bichro- 
mate; a yellow precipitate will confirm the presence of lead; to the other add 
a few drops of a solution of potassium ferrocyanide, when a brown precipitate 
or coloration will indicate presence of copper. The filtrate from the residue after 
the above fusion is acidulated with acetic acid, when a yellow precipitate of stannic 
sulphide will indicate the presence of tin. The latter test may be confirmed by 
dissolving the precipitate of stannic sulphide in hydrochloric acid and bromin- 
water. The filtered solution is then boiled with small pieces of metallic iron to 
reduce the tin; the liquid is diluted and filtered and a droj) of mercuric chloride 
solution is added, when a white or gray turbidity will be produced if tin is present. 

t Japan tram silk is frequently weighted with fatty substances. The normal 
amount of fat in raw silk never exceeds 0.06 per cent. A direct determination 
of the fatty matters may be made by treating 5 grams of the silk sample in a stop- 
pered flask with pure benzene three or four times successively, using about 60 
c.c. of the solvent each time and allowing it to act from two to four hours with 
frequent .shaking. The several portions of benzene are brought together and 
evaporated to dryness in a tared dish and the fatty residue is weighed. Another 
method is to extract with ether in a Soxhlet apparatus. 



QU/iNTlTATll^E /I N^ LYSIS OF THE TEXTILE FIBRES. 261 

ish color not changed to violet by addition of lime-water, it is 
safe to conclude that the silk has been weighted by alternate 
passages through baths of iron salts and tannin. The yellow 
color of the fibre is due to a residuum of tannin, and the precise 
shade (from greenish to brownish yellow) enables some idea to 
be formed as to the nature of the tanning material used (sumac, 
divi-divi, cutch, etc.). Decolorization of the fibre, the acid 
extract being pink, and changing to violet by lime-water, indi- 
cates a logwood black. If the fibre retain a deep greenish tint 
and the solution be yellow and unaffected by lime-water, the 
black is dyed on a bottom of Prussian blue. If the latter has 
been produced during the linal stage of dyeing, this will be shown 
by its solubility in the acid. x\ green fibre and pink solution, 
changing to violet on addition of hme-water, indicate a logwood 
black dyed on a bottom of Berlin blue. In the hydrochloric 
acid solution, such metals as lead, tin, iron, chromium, and alu- 
minium may be determined. Blacks produced by artificial dyes 
on a bottom of iron-tannin or iron-blue-tannin mav be recomized 
by the coloration imparted to acid and caustic soda solutions. 
With blacks produced solely with coal-tar dyes, treatment with 
a hydrochloric acid solution of stannous chloride does not affect 
anilin and alizarin blacks; naphthol black is changed to reddish 
brown, and wool black becomes yellowish brown. Tannin mate- 
rials in general may be extracted by alkalies, and subsequently 
precipitated and distinguished by ferric acetate. To remove the 
whole of the weighting material and the dye, the silk should be 
boiled with acid potassium oxalate, washed with dilute hydro- 
chloric acid, and finally treated with soda solution. When iron 
and tin are both present in the fibre, it is best to first extract the 
tin by treatment with a solution of sodium sulphide.* 

Vignon has proposed using the specific gravity of the silk 
sample as a means of determining the proportion of weighting 
materials present; but this method cannot be recommended as 

* Persoz recommends in testing for tin weighting on dark colored and black 
silks to boil the sample for a few minutes in concentrated hydrochloric acid. Then 
dilute and filter the acid, and pass hydrogen sulphide into it, when a yellow pre- 
cipitate (SnS) would indicate the presence of tin. 



262 THE TEXTILE FIBRES. 

being at all practical, .as the specific gravity of the weighting 
materials themselves would have to be known. The specific 
gravity of the silk may readily be determined as follows: A small 
sample is weighed as usual in the air; it is then suspended in 
benzene and the weight again taken. The difference between 
the two weighings will give the loss of weight in benzene; this 
loss divided into the original weight in air and multiplied by the 
density of the benzene will give the specific gravity of the silk. 
The specific gravity of silk and of other fibres determined in this 
way is given as follows: 

Silk, raw i . 30 to 1.37 

Silk, boiled-off i • 25 ' 

Wool 1 . 28 to 1 . 33 

Cotton 1 . 50 to 1 . 55 

Mohair i . 30 

Hemp 1 . 48 

Ramie 1.51 to 1.52 

Linen 150 

Jute 1 . 48 

For the examination of white silk Allen recommends the 
following:* (i) The total soluble weighting materials are deter- 
mined by treating a known weight of the sample four to five times 
with hot water, redrying, and weighing. As the hygroscopic 
character of silk is very variable, it is best to employ a blank 
sample of a standard silk, and after redrying until the blank 
sample has regained its normal weight the test sample is weighed, 
and the loss represents the matters soluble in water. In the 
solution, after suitable evaporation, glucose may be determined 
directly by means of Fehling's solution (see p. 259), and cane- 
sugar after inversion by boiling with dilute hydrochloric acid. 
Sulphates and chlorides and magnesium f may be detected and 

* Commer. Org. Anal., vol. iv. 527. 

f Sulphates are detected by taking a small portion of the solution in a test- 
tube, adding a few drops of dilute hydrochloric acid and then a few drops of a 
solution of barium chloride; the production of a white precipitate indicates the 
presence of sulphates. Chlorides are detected by adding a drop of nitric acid 
to a test portion of the solution, and then a few drops of a solution of silver ni- 
trate; a white precipitate will indicate the presence of chlorides. Magnesium 
is detected by adding to the test portion of the solution a few drops of ammonia 



QUANTITATiyE ANALYSIS OF THE TEXTILE FIBRES. 263 

determined as usual. Stannic oxide (if the silk has been weighted 
with tin compounds) will be left as a white residue on igniting a 
sample of the silk in a porcelain crucible. If much tin is present, 
the silk will bum with difficulty, and the ash will retain the shape 
of the original silk. The weight of the ash (assuming it to be 
wholly stannic oxide, SnOj) may be calculated to the form in 
which the tin exists in the weighted silk (as metastannic acid, 
Sn02.H20) by multiplying it by the factor 1.12. 

Silbermann * recommends for the analysis of white silk the 
further procedure: A weighed portion of the silk is boiled with 
dilute hydrochloric acid to dissolve any tannin lakes of tin or 
other metals, and in the solution tannin is tested for by the addi- 
tion of an excess of sodium acetate and ferric chloride. If tannin 
lakes are present, the determination of the weighting materials 
consists in: (i) precipitation of the tannin from the aqueous 
solution with gelatin; (2) estimation of the tannin in this pre- 
cipitate, and of sugar, etc., in the filtrate; (3) successive treat- 
ment of the silk with dilute hydrochloric acid and sodium car- 
bonate, and precipitation of tannin from both solutions by means 
of gelatin; (4) ignition of the silk and determination of metallic 
weighting. If the ash is not completely soluble in hot moder- 
ately concentrated hydrochloric acid, it may contain barium 
sulphate or siHca. To calculate the percentage of weighting 
material, W, in the silk examined, Silbermann employs the fol- 
lowing formula, in which a is the weight of the sample before 
treatment, h the weight after extraction with water, p the stannic 
oxide left on ignition, and d the loss in weight during the boihng 
of the fibre itself. This is taken at 20 to 25 for boiled-off silk, 
5 to 9 for souple silk, and o to 2 for ecru. 

a{ioo-d) 

W = T — 100. 

6- 1. 13/' 

followed by a solution of sodium phosphate; the formation of a white precipi- 
tate indicates the presence of magnesium. These tests may be made quantita- 
tive by taking definite aliquot portions of the solution, collecting the precipitates 
produced, and after ignition in a porcelain crucible weighing as barium sulphate, 
BaSO^, silver chloride, AgCl, and magnesium pyrophosphate, Mg^P^O^, re- 
spectively. 

* Chem. Zeit., xx. 472. 



264 THE TEXTILE FIBRES. 

The detection of tin or aluminium compounds in the weight- 
ing of white silk may be carried out by dyeing a sample of the 
silk with alizarin in the presence of chalk, then rinsing and soap- 
ing. Unweighted silk will retain only a pink color; if weighted 
with tin, the color will be orange, and if weighted with aluminium, 
the color will be red. 

Dark colored and black silk may contain hydroxides of tin, 
iron, and chromium, fatty matters, tannin, Prussian blue, and 
various coloring- matters. Treatment of logwood-dyed silk with 
hydrochloric acid (1.07 sp. gr.) at 50° to 60° C. will give a red 
color in the absence of Prussian blue, or leave a blue-black color 
if it is present. If Prussian blue is suspected, the silk should be 
treated with dilute caustic soda, the solution then acidulated 
with hydrochloric acid, and a few drops of a solution of ferric 
chloride then added ; a blue precipitate will be produced if Prussian 
blue was originally present. The metallic oxides in the residue 
left on igniting a sample of the silk are best examined by fusing 
the ash with a mixture of nitre and sodium carbonate in a plati- 
num or silver crucible. The fusion is treated with water, when 
the tin and chromium will go into solution as sodium stannate 
and chromate respectively, and the iron will remain insoluble as 
ferric oxide. After filtering and acidulating the filtrate with 
hydrochloric acid, the tin may be thrown down as sulphide by 
treatment with hydrogen sulphide, and after filtering off the latter 
the chromium is precipitated by addition of ammonia. For the 
detection of tannin a sample of the silk should be boiled in water, 
and a few drops of a solution of ferric acetate added, when a 
blue-black color is produced in the presence of tannin. The 
amount of tannin may be determined by dissolving it from the 
silk by means of an alkaline soap-bath, and finding the loss of 
weight on redrying. To determine the total proportion of 
weighting materials, a definite quantity of the silk dried at 110° C. 
should be boiled for an hour in a 2 per cent, solution of caustic 
soda, and then in dilute hydrochloric acid (250 c.c. of commer- 
cial acid per litre). This treatment is repeated four times, wash- 
ing the sample between each bath. The silk must be carefully 
handled, as it becomes quite brittle; after drying at 110° C. it 



QUANTITATIVE ANALYSIS OF THE TEXTILE FIBRES. 265 

is weighed; the loss in weight represents the total weighting 
materials. As a certain loss of silk occurs in this treatment, the 
amount of weighting material found is generally somewhat in 
excess of the truth. The chief source of error, however, is in 
the uncertainty of the allowance to be made for loss in the weight 
of the silk by boihng off. For boiled-off silk this figure {d) is 
taken at 25 per cent.; for souple silk at 8 per cent.; for ecru at 
o per cent.; and for fancy silks at 10 per cent. CalHng p the 
original weight of the sample, and D the weight after treatment, 
the percentage of weighting, W, may be calculated from the fol- 
lowing formula: 

{100- d)X{p-D) . 
D 

In cases where the treated silk leaves a sensible amount {A) of 
ash on ignition, the following formula must be used: 

(^-D+i.25^)X(ioo-^) 
D-1.2SA 

as the weight of the ash, if multiplied by the factor 1.25, will give 
approximately the amount of rnetallic hydroxides retained by 
the treated silk. 

The foregoing method of Silbermann is not sufficiently accu- 
rate for such a long and tedious process. 

The method of analyzing weighted silk recommended by 
Konigs of the silk-conditioning establishment at Crefeld is as 
follows: (i) Determine moisture by drying at 110° C. (2) Fatty 
matters by extraction with ether. (3) Boil out the silk-glue with 
water. (4) Dissolve out Prussian blue with dilute caustic soda; 
reprecipitate by acidifying and adding ferric chloride, ignite pre- 
cipitate with nitric acid, and weigh as ferric oxide; i part of 
Fe203 = i.5 parts of Prussian blue. (5) Estimate stannic oxide in 
ash of silk and calculate as catechu- tannate of tin; i part of 
Sn02 = 3.33 parts of catechu-tannate. (6) Estimate total ferric 
oxide in ash, subtract that existing as Prussian blue, and the 
amount naturally present in dyed silk (0.4 to 0.7 per cent.), and 
calculate the remainder to tannate of iron; i part of Fe203 = 7.2 
parts of ferric tannate. 



^266 THE TEXTILE FIBRES. 

Perhaps the most accurate method of analyzing silk for total 
amount of weighting is to determine the amount of nitrogen 
present as silk by Kjeldahl's process.* To do this it is first nec- 
essary to remove all gelatin, Prussian blue, or other nitrogenous 
matters. This is eiiected by boiling a weighed quantity of the 
silk (about 2 grams) with a 2 per cent, solution of sodium carbonate 
for thirty minutes. The silk is then washed, and heated to 60° C. 
for thirty miniites in water containing i per cent, of hydrochloric 
acid, and afterwards well washed in hot water. This treatment 
with alkali and acid should be repeated until the sample no longer 
has a blue color. With souple or ecru silks, ammonia or ammo- 
nium carbonate should be used instead of sodium carbonate, 
and the silk should be finally boiled for an hour and a half in a 
solution containing 25 grams of soap per Htre. After this prepara- 
tion the nitrogen determination is conducted as follows: The 
sample is placed in a round-bottomed flask of hard glass, and 
treated with about 20 c.c. of strong sulphuric acid, with the addi- 
tion of a single drop of mercury. The flask is then heated, gently 
at first, and then to a vigorous boil; then 10 grams of potassium 
sulphate are added and the boiling continued until the contents 
of the flask are clear and colorless. The contents are then 
washed into a distilling-flask and connected with a suitable con- 
denser. By means of a tap-funnel an excess of caustic soda 
solution is gradually added, together with a little sodium sul- 
phide to decompose any nitrogen compounds of mercury that 
may have been formed. Some granulated zinc is placed in the 
flask to prevent bumping, and the distiUate is collected in a meas- 
ured quantity of standard acid, which takes up the ammonia 
that distils over. Excess of acid is determined by titration with 
standard alkaH, using methyl orange as an indicator of neutral- 
ity. The above method is based on the fact that when silk (in 
common with the great majority of other nitrogenous organic 
substances) is heated with concentrated sulphuric acid, the whole 
of the nitrogen present is eventually converted into ammonia. 
Air-dried silk with 11 per cent, of hygroscopic moisture contains 



* Gnehm and Blenner, Rev. Gen. Mat. Col.^ April, if 



QU^hlTITATiyE ANALYSIS OF THE TEXTILE FIBRES. 267 

17.6 per cent, of nitrogen, consequently the amount of true silk 
in a sample may be obtained by multiplying the percentage of 
nitrogen found by the factor 5.68. This method yields very accu- 
rate results if the determination of the nitrogen is carefully con- 
ducted. 

A method for the determination of the weighting on silk 
which appears to be capable of yielding very good results is that 
suggested by Gnehm.* It depends on the fact that the silk 
fibre does not appear to be injured by treatment with either 
hydrofluosilicic acid or hydrofluoric acid. The method is car- 
ried out as follows : About 2 grams of the silk to be tested are im- 
mersed, with frequent stirring, for one hour at the ordinary tem- 
perature in 100 c.c. of a 5 per cent, solution of hydrofluosihcic 
acid. The treatment is then repeated with 100 c.c. of fresh acid 
of the same strength. The silk is then washed several times 
with distilled water and dried. The loss in weight corresponds 
to the amount of inorganic weighting materials present. This 
method serves very well with silk weighted with stannic phos- 
phate and silicate, but does not appear to be suitable for the 
estimation of weighting on black-dyed silks containing iron salts. 
It is said that oxalic acid may also be used (Miiller, Zeits. Farben- 
u. Text. Chem., 1903, 160) for the purpose of removing the inor- 
ganic weighting materials from silk, without injury to the silk 
fibre itself. 

* Zeits. Farben~u. Text. Chem., 1903, 209. 



APPENDIX I. 

MICROSCOPIC ANALYSIS OF FABRICS. 

HoHNEL describes the following method employed for a micro- 
scopic examination of textile fabrics, where the object is to deter- 
mine not only qualitatively the character of fibres composing 
them, but also their quantitative amounts. With regard to the 
preliminary qualitative examination, there are generally only a few 
fibres to be taken into consideration, as there seldom occur in the 
same fabric more than one to four different kinds of fibres. As 
a rule, the only fibres which will be found are cotton, linen, hemp, 
jute, ramie, sheep's wool, goat-hair, cow-hair, angora, alpaca, 
cashmere, llama, silk, and tussah silk. In woolen material 
there are also cosmos and shoddy to be considered. 

To undertake the examination, cut off a sample of the mate- 
rial 2 to 3 sq. cm. in size, and separate this into its warp- and fill- 
ing-threads. The sample must be of sufficient size to include 
all of the different kinds of yarns employed in the weave. Con- 
sequently in the case of large patterns it has to be rather large. 
The warp- and filling-threads are laid next to each other, and one 
of each kind is selected to serve for further examination. In the 
simplest case there is only one kind of warp-thread and one kind 
of fining present, which necessitates, therefore, the examination 
of only two different yarns. In complicated cases there may be 
as many as ten, or even more, different yarns to analyze. In 
woolen fabrics there will frequently be found yarns - which are 
composed of two or three different threads twisted together; 
these must be untwisted and each separate yarn examined by 
itself. In order to attain satisfactor}' results, the operator must 
be sufiiciently skilled in the microscopy of the fibres to be able to 
recognize with certainty, under a low magnification, the different 

269 



2 70 yiPPENDIX I. 

fibres liable to be found. By a low magnification is meant one 
of fifty to sixty times. A much higher power cannot be used in 
the examination of fabrics, for hundreds or even thousands of 
fibres have to be taken into consideration. From ten to twenty 
fibres, or perhaps more, should be obtained in the field at the 
same time, and it is necessary to be able to promptly recognize 
the different ones. With a higher magnification, it is true, the 
single fibres can be better recognized, but the general view is 
then lost, and there is danger in overlooking whole bundles of 
fibres. If the observer finds a fibre which cannot be recognized 
with sufficient accuracy by means of the low power, it is a simple 
matter to so change the objective as to increase the magnification 
to allow of the necessary observations to be made, and then to 
proceed again with the examination under the lower power. 

Dark colored material often consists for the most part of 
threads which, on microscopic examination, appear quite opaque, 
hence dark and structureless. Therefore it will frequently be 
necessary to remove the dyestuff, at least in part, which is usually 
done by boiling in acetic acid, hydrochloric acid, dilute caustic 
alkah, potassium carbonate, etc., until sufficiently light in appear- 
ance. 

In the case of very accurate examinations, each different kind 
of thread must be examined separately, and the number of fibres 
composing it, together with their kind and color, must be noted. 
In order to show the detail and scope of such an examination, the 
following example is given: On unravelling a sample four differ- 
ent warp-threads and one filling-thread were obtained. One of 
the warp-threads was composed bf two yarns twisted together, 
one of which was black {K^a) and the other white {K^h). 
Two warp-threads were dark blue {K^ and K^ and the fourth 
was a gray mix {K^ ; the filHng-thread {E) was blue. On exam- 
ination the following results were obtained: 

K^a showed 85 shoddy fibres (mostly black, some yellow and 
red, and even isolated green fibres of wool, and 13 cotton fibres). 

K-^h showed 31 pure white wool fibres. 

K^ and K^, respectively, showed 46 and 53 pure blue wool 
fibres. 



MICROSCOPIC /IN A LYSIS OF FABRICS. 271 

Ki showed 60 shoddy fibres, of which 32 were mostly gray or 
black wool fibres, and 28 were gray cotton fibres. 

E showed 60 blue wool fibres. 

Therefore in this sample, including 4 warp- and 4 filling- threads, 
there would be 85 -f3i + 46 -1-53 + 60=275 single warp fibres; 
and 60 X 4 = 240 filling fibres ; or 5 1 5 single fibres altogether. Of 
these 41 were cotton, which were found in the shoddy, the latter 
comprising 145 fibres in all. Hence in a sample of this piece of 
goods containing equal lengths of warp and weft, there are 41 
cotton fibres, 104 shoddy- wool fibres, and 370 pure- wool fibres, 
from which the respective percentages would be : 

Per Cent. 

Cotton 8.0 

Shoddy- wool 20 . 2 

Pure-wool 71.8 



100. o 



This, of course, only gives the relative percentages of the 
number of fibres; if it is desired to reach an approximate idea of 
the proportions by weight, then micrometric measurements must 
be made of the wool and cotton fibres occurring in the sample. 
In consideration of the fact that wool possesses about twice the 
cross-section of cotton, it becomes a rather easy matter to calcu- 
late the ratio between the two, by means of which the percentage 
by weight can be readily obtained, provided that the specific 
gravity of wool is taken to be about the same as that of cotton, 
which is approximately true. 



APPENDIX II. 

MACHINE FOR DETERMINING STRENGTH OF FIBRES. 

There have been a number of machines devised for the pur- 
pose of determining the tensile strength and elasticity of fabrics 
and yarns, and a few instruments have also been adapted for 
the testing of single fibres. As the individual fibre, however, is 
a very slender and delicate object, especially in the case of cer- 
tain vegetable fibres, the determination of its physical factors is 
an operation which requires a delicately adjusted apparatus. In 
machines which require the taking on or off of weights, the jar is 
usually sufficient to break the fibre before its true breaking strain 
is reached. The same criticism is also true for machines employ- 
ins water as a weight. A machine devised for the use of the 
Philadelphia Textile School has proved very satisfactory for 
determining the tensile strength and elasticity of almost any 
fibre, from very fine and delicate filaments to coarse and strong 
hairs. A diagrammatic drawing of this machine is given in Fig. 
69. The fibre to be tested is clamped between the jaws at (/), 
the pointer attached to the end of the beam above the upper jaw 
being brought to the zero- mark on the scale (S), while the lower 
jaw is raised or lowered in its stand until the desired distance 
between the jaws is obtained. To obtain comparable results this 
distance should always be the same; and 10 cm., in the case of 
long fibres, or 2 cm. for short fibres, have proved to be good 
lengths of fibre to test. The sliding-bar (R) is moved forward by 
turning the rod (T), which moves the rack and pinion at (P), 
until the graduation on the wheel (G) is at zero to the indicator. 

Under these conditions there is no strain on the fibre. A stretch- 

272 



M/f CHINE FOR DETERMINING STRENGTH OF FIBRES. 



273 



ing-force is then placed on the fibre by moving the bar (R) back- 
ward by turning the rod (T); the motion of this bar is made 
uniform and gradual until the fibre finally breaks under the strain 
thus placed upon it. The graduation on the wheel (G) will 
then indicate in decigrams the breaking strain of the fibre being 
tested. The elasticity is obtained by watching carefully the 
pointer moving up the scale of millimeters at (S) until the rupture 




Fig. 69. — Fibre-testing Machine of Reeser & Mackenzie. 

J, jaws wath screw-clamps for holding the fibre; the lower jaw may be raised or 
lowered; R, sliding-rod working on a rack and pinion; this takes the place 
of weights; G, wheel graduated on its face in decigrams, moving on the 
same axis as the pinion for sliding the weight; T, thumb-screw for turning 
the small shaft working the pinion at P; W, counterbalancing weight for 
regulating the zero-point of the machine; S, scale for reading the stretch of 
the fibre. 

of the fibre takes place; the distance this pointer moves represents 
the actual stretch of the fibre; and if the length of fibre taken 
between the jaws is 10 cm., this figure will represent directly the 
percentage of elasticity. If the length of fibre taken is only 2 cm., 
to obtain the percentage of elasticity it is necessary to multiply 
the amount of stretch in millimeters by five ; and for other lengths 
of fibre similar proportions will hold. The weight (W) at the 
rear end of the beam can be moved backward or forward, and 
is for the purpose of adjusting the balance so that there is no 
strain at (/) when the indicator on (G) marks zero. The wheel 



2 74 y^PPENDJX II. 

(G) is graduated in decigrams, and this marks the sensibility of 
the machine; the total graduations on (G) running from zero to 
400. When fibres are tested having a greater tensile strength 
than 400 decigrams a fixed additional weight of 10, 25, 50, etc., 
grams may be hung from (W), and this must be added to the 
reading on the wheel when the fibre breaks. If the elasticity of 
the fibre is so great as to carry the pointer beyond the limits of 
the scale at (5), a shorter length of fibre must be tested. A fair 
average of breaking strain and elasticity may be obtained for 
any quality of fibre by testing about 10 separate fibres and taking 
a mean of the total tests. If the quality of the fibres, however, 
in a sample does not run very uniform, it is best to increase the 
number of tests to 25 or even 50 in order that a satisfactory 
average may be obtained. 

This machine is capable of being used with all classes of fibres, 
and its results are very satisfactory, as has been proved by several 
years' use at the Philadelphia Textile School.* 

* This machine is made by Reeser & Mackenzie of Philadelphia. 



APPENDIX III. 

BIBLIOGRAPHY OF THE TEXTILE FIBRES. 

Allen. Commercial Organic Analysis, vol. i, and vol. in, part iii. 

Philadelphia, 1898. 
Berthold. Ueber die mikroskop. Merkmale der wichstigen 

Pflanzenfasem. 1883. 
Bolley. Beitrage zur Theorie der Farberei. 
Bolley. Untersuchung ueber die Yamamayseide. Polyt. Zeit- 

schrift, 1869, p. 142. 
Bolley and Schoch. Ueber die Seiden. Dingl. Polyt. Jour., 

1870, p. 72. 
Biesiadecky. Artikel Haut, Haare, und Naegel in Strieker's 

Handbuch der Lehre von den Geweben. Leipzig, 187 1. 
Browne. Trichologia mammalium. Philadelphia, 1853. 
Bottler. Die vegetabilischen Faserstoffe. Leipzig, 1900. 
Bottler. Die animahschen Faserstoffe. Leipzig, 1902. ^ 

Bowman. The Structure of the Wool Fibre. 
Bowman. The Structure of the Cotton Fibre. 
Beech. Dyeing of Cotton Fabrics, pp. 1-22. London, 1901. 
Beech. Dyeing of Woolen Fabrics, pp. 1-14. London, 1902. 
Cross and Bevan. Cellulose. London, 1895. 
Cross and Bevan. Researches on Cellulose, 1895 to 1900. Lon- 
don, 1 90 1. 
Cross and Bevan. Paper Making, pp. i-iio. London, 1900. 
Christy. New Commercial Plants and Drugs. 1882. 
Cuniasse et Zwilhng. Essais du Commerce; Matieres textiles, 

pp. 225-232. Paris, 1901. 

275 



276 . APPENDIX III. 

Clark. Practical Methods in Microscopy. Boston, 1900. 
Dodge. Descriptive Catalogue of the Useful Fibre Plants of the 

World. Report No. 9 of the U. S. Dept. of Agriculture. 

1897. 
Dodge. Report on Flax Culture. No. 10, U. S. Dept. of Agri- 
culture. 1898. 
Eble. Die Lehre von die Haaren. 2 vols. Vienna, 183 1. 
Engel. Ueber das Wachsen abgeschnittener Haare. 1856. 
Erdl. Vergleichende Darstellung des inneren Baues der Haare. 

1841. 
Editors of the "Dyer and Calico Printer." Mercerisation. Lon- 
don, 1903. 
Frey. Das Mikroskop fiir Aerzte, etc. 
Grothe. " Textil Industrie " in Muspratt's Chemie, vol. v. 
Gurlt. Vergleichende Untersuchungen ueber die Haut. Berlin, 

1844. 
Gardner. Die Mercerisation der Baumwolle. Berlin, 1898. 
Garden. Wool Dyeing, part i, pp. 7-19. Philadelphia, 1896. 
Georgevics. Chemical Technology of the Textile Fibres. Trans. 

Salter. London, 1902. 
Gnehm. Taschenbuch fiir die Farberei und Farbenfabriken: 

" Gespinnstfasern," pp. 1-17. Berlin, 1902. 
Hummel. Dyeing of the Textile Fibres. London, 1896. 
Hannan. Textile Fibres of Commerce. London, 1902. 
Hohnel. Die Mikroskopie der technische verwendeten Faser- 

stoffe. Leipzig, 1887. 
Hohnel. Die Unterscheidung der pflanzlichen Textilfasem. 

Dingl. Polyt. Jour., ccxlvi, 465. 
Hohnel. Ueber pfianzliche Faserstoffe. Vienna, 1884. 
Hohnel. Ueber den Bau und die Abstammung der Tillandsia- 

faser. Dingl. Polyt. Jour., ccxxxiv, 407. 
Hohnel. Beitrage zur technischen RohstofHehre. Dingl. Polyt. 

Jour., ccLii. 
Hoyer. Das Papier, seine Beschaffenheit und deren Priifung. 

Muenchen, 1882. 
Hanausek und Nebeski. Mikroskopie von Pelzhaaren. Jahres- 

bericht der Wiener Handelsakademie. 1884. 



BIBLIOGRAPHY OF THE TEXTILE FIBRES. 277 

Halphen. La Pratique des Essais commerciaux ct inclustriels 
Matieres organiques. " Textiles et Tissues," pp. 326-342. 
Paris, 1893. 

Heermann. Dyers' Materials: "Textile Fibres," pp. 16-24. 
Trans. Wright. London, 1900. 

Janke. Wool production. 1864. 

Joclet. Chemische Bearbeitung der Schafwolle. Leipzig, 1902. 

Knecht, Rawson, and Loewenthal. Manual of Dyeing, vol. i, 
pp. 1-57. London, 1893. 

Karmarsh. Technisches Worterbuch. Artikel " Baumwolle " und 
"Gespinnstfasern." 1876. 

Kolliker. Handbuch der Gewebelehre. 

Leydig. Lehrbuch der Histologie. 

Lafar. Technical INiycology, vol. i. London, 1898. 

Lunge. Chemische technische Untersuchungsmethoden, vol. iii, 
pp. 1026-1056. Berhn, 1900. 

Monie. The Cotton Fibre. London, 1890. 

Nathusius-Konigsborn. Das Wollhaar des Schafes in histolo- 
gischen und technischen Beziehung. Berlin, 1866. 

Orschatz. Ueber den Bau der wichtigsten verwendbaren Faser- 
stoffe. Polyt. Centralblatt, p. 1279. 1848. 

Rohde. Beitrage zur Kenntniss des Wollhaares. Eldenaer 
Archiv. 1856, 1857. 

Rawson, Gardner, and Laycock. Dictionary of Dyes, Mor- 
dants, etc.; articles relating to Textile Fibres. London, 
1901. 

Schlesinger. Examen microscopique et microchemique des Fibres 
textiles. Paris, 1875. 

Schacht. Die Priifung der im Handel vorkommenden Gewebe. 
Berlin, 1853. 

Schmidt. Schafzucht und WoUkunde. 1852. 

Siivern. Die kiinstliche Seide. Berhn, 1900. 

Sadtler. Handbook of Industrial Organic Chemistry. Phila- 
delphia, 1897. 

Sansone. Dyeing Wool, Silk, Cotton, etc., vol. i, pp. 18-32. 
London, 1888. 

Sansone. Printing of Cotton Fabrics, pp. 53-73. London, 1901. 



278 APPENDIX III. 

Thorpe. Dictionary of Applied Chemistry; articles relating to 

Textile Fibres. New York, 1895. 
United States Report. The Cotton Plant. Bulletin No. ^ '^ 

Dept. of Agriculture, 1896. 
Vetillard. Etudes sur les Fibres vegetales textiles. Paris, 1876. 
Vignon. La Soie. Paris, 1890. 
Witt. Chemische Technologic des Gespinnstfasern, part i. 

Braunschweig, 1891. 
Wiesner. Die Rohstoffe des Pflanzenreiches, vol. 11, " Fasern." 

Leipzig, 1903. 
Wiesner. Beitrage zur Kenntniss der indischen Faserpfianzen. 

1870. 
Wiesner. Einleitung in die technische Mikroskopie. 1867. 
Wiesner und Prasch. Ueber die Seiden, in Mikroskop. Unter- 

suchungen, 1872, p. 45; und Dingl. Polyt. Jour., p. 190. 

1868. 
Wagner. Handbuch der Physiologic. Artikel " Der Haut." 
Wagner. Chemical Technology: " Fibres," pp. 798-871. Trans. 

Crookes. New York, 1897. 
Wertheim. Ueber den Bau des Haarbalges. Vienna, 1864. 



INDEX. 



Abaca fibre, 202 

Abelmoschiis tetraphyllos, 99 

Abutilon avicennce, 184 

Acid-proof fabrics, 172 

Adamkiewitz's test for proteids, 88 

Adipocelluloses, 146 

African cottons, 119, 125, 127 

African sheep, 7 

Agave americana, 100, 203 

decipius, 192 

fcetida, 192 

lieteracantha. 192 

rigida, 192, 203 
Agerian cotton, 125 
Ailanthus silk, 74 

action of polarized Ught on, 223 
Alabama cotton, 127 
Alkali-cellulose, 145, 157 
Allanseed cotton, 126 
Aloe fibre, 203 

hemp, 239, 242 
Aloe perjoliata, 99, 109 
Alpaca, 6, 59 

microscopy of, 60 
Ambari hemp, 191, 198 
American cotton, varieties of, 126 

merino wool, 15 

wools, shrinkage of, 25 
Amido-cellulose, 152 
Amido group in wool, evidence of, 35 
Ammoniacal nickel oxide solution for 

fibre-testing, 211 
Amyloid, 144 
Angola sheep, 7 
Angora goat, 6 
Animal and vegetable fibres, distinction 

between, 2 
Animal fibres, i 

Lieberman's test for, 212 
Animalized cotton, 175 
Anther cea assama, 74 

mylitta, 74 

pernyi, 74, 222 

yama-mai, 74 



Antiphlogin, 171 
Apocynum cannibinum, 192 
Argali, 6 

Arryndia ricini, 222 
Artificial fibres, i 

classification of, 3 

horse -hair, 148 

silks, 4 

chemical reactions of, 175 
comparison of, 174 
identification of, 217, 220 
manufacture of, 171 
tensile strength of, 175 

wool, 50 
Asbestos, 2 
Asclepias cornutii, 228, 243 

cotton, 122 

curassavica, 122, 228, 244 
Ash in various cottons, 141 

of cotton, analysis of, 141 

of jute, analysis of, 186 

of wool fibre, analysis of, 34 
Assam cotton, 128 
Attacus atlas, 74 

lunula, 222 

ricini, 74 
Auchenia huanaco, 61 

llama, 61 

paco, 59 

viccunia, 61 
Australian botany wool, 15 

cotton, 127 

B. 

Bahia cotton, 126 

Bamboo papers, 105 

Barbadoes cotton, 115 

Barwall sheep, 7 

Basinetto silk, 72 

Bass fibres, 104 

Bast fibres, 97, 100, 106, 232 

reactions of, 217, 218 

structure of, 98 
papers, 105 
Bastose, 185, 186 



379 



INDEX. 



Bauhinia racemosa, 99, 109 

Bave, 73 

Bearded sheep of west Africa, 7 

Beard-hair of sheep, 8 

Beaumontia grandiflora, 122, 228 

Benders cotton, 127 

Bengal cotton, 119, 125, 128 

hemp, 191 
Bhownuggar cotton, 128 
Bibhography of the textile fibres, 275 
Big-horn sheep, 6 
Bilatee cotton, 128 
Biuret test for proteids, 88 
Black-faced sheep of Thibet, 7 
Black-fellows hemp, 191 
Bcehnieria nivea, 99, 188 

tenacissima, 99, 188 
Boiled-off liquor, 85 

use of, 81 
" Bolton counts," 116 
Bombax ceiba, 121, 231 

cotton, 121, 244 

heptaphyllum, 99, 121, 231 

malabaricum, 121 

pentandrum, 121 
Bombay hemp, 191 
Bombyx mori, 69 
Bourbon cotton, 128 
Bourette silk, 84 
Boweds cotton, 127 
Bowstring hemp, 191 
Brazilian cotton, varieties of, 126 

sheep, 7 
Brins, 73 

Broach cotton, 119, 125, 127 
Broad-tailed sheep, 7 
Bromelia karatas, 99, 100, 109 

pinguin, 100 
Broom fibres, 104 
Broom-grass fibre, 100 
Brown Egyptian cotton, 119, 125, 126 

hemp, 191 
Brush fibres, 103 

C. 

Cago sheep, 7 

Calabria cotton, 128 

Calcium pectate, 179 

Calcutta hemp, 191 

Calotropis gigantea, 99, 109, 122, 228 

procera, 228, 243 
Camel's hair, 62 
Cannabis gigantea, 192 

sativa, 99, 100, 192 
Carbohydrates, 143 
Carbonization of wool-silk goods, 31 
Carbonizing, 51 
Carthagenian cotton, 127 
Cashmere, 6, 57 
Cat-hair, 65 



Caulking fibres, 105 

Caustic alkali solution for fibre-testing 
211 

soda, absorption of wool for, 35 
action of, on wool, 39 
Ceara cotton, 120, 125, 126 
Cebu hemp, 191 
Ceiba cotton, 231 

Cells of wool fibre, dimensions of, 19 
Celluloid, 150 
Cellulose, 142 

chemical constitution of, 144 

properties of, 143 

acetate, 145 

benzoate, 146 

hydrate, 156 

nitrate, 146 

sulphate, 146 

tetracetate, 146 

thiocarbonate, 145 

xanthate, 145 
Chappe silk, 84 
Chardonnet silk, 171 
Chemical analysis of cloth, 248 

yarn, 250 
China-grass, 99, 109, 188, 233 
Chinese cotton, 114, 121, 125, 127 

jute, 184 

sheep, 7 
Chlored wool, applications of, 41 

preparation of, 42 

properties of, 41 
Cholesterol, ^iT, 
Chorisia speciosa, 121 
Cibotium glaucum, 122 
Classification of fibres, i 
Cocoanada cotton, 128 
Cocas niicifera, 100 

Cochineal tincture for fibre-testing, 209 
Cochlospernum gossypium, 244 
Cocons silk, 72 

Coefficient of acidity of various fibres, 35 
Coir fibre, 99, 100, 241 

uses of, 207 
Collodion, 150 

silk, 172 
Colorado river hemp, 191 
Coloring-matter in cotton, 140 

wool, 34 
Common hemp, 192 

sheep, 6 
Commersonia fraseri, 191 
Compound celluloses, 146 
Comptah cotton, 119, 125, 127 
Conditioning apparatus, 47 

houses, 45 

of wool, 45 
Congo sheep, 7 
Copper sulphate solution for fibre-testing, 



INDEX. 



281 



Corchori'.s capsiilaris, 99, 100, 184 
decemangulatus, 184 
J use us, 184 
itorius, 99, 184 
Cordage fibres, 103 

strength of, 197, 207 
Cordia latijolia, 99, 109 
Cortical layer in wood fibre, 19 
Coryph.i umbraculijera, 100 
Cosmos fibre, 51 
Cotted fleeces, 32 
Cotton, 99, 109, 225, 233, 243 
action of alkalies on, 151 
ammonia on, 152 
coloring-matters on, 154 
heat on, 147 
metallic salts on, 154 
mineral acids on, 149 
organic acids on, 151 
oxidizing agents on, 154 
sulphides on, 153 
tannin on, 151 
chemical reactions of, 147 
dry distillation of, 147 
effect of bleaching on, 155 
fermentation of, 154 
origin and growth of, no 
physical structure of, 124 
and linen, distinction between, 213 
fibre, capillarity of, 124 
chemical properties of, 139 
conditions determining quality of, 

114 
diameter of, 125, 129 
length of, 125, 129 
microscopic properties of, 132 
mineral matter in, 139 
number of twists in, 124 
physiological development of, 112 
staple of, 130 
structure of, 131 
Cotton-grass, 106, 225 
Cotton-oil, 139 
Cotton plant, no 
Cotton-silk, 123 
Cotton-tree, 121 
Cotton-wax, 139 

analysis of, 140 
Cotton-wool, 99 
Count of cotton yarn, 117 
Courtrai flax, 178 
Cow-hair, 58, 62 

microscopy of, 64 
Chromic acid, action of, on wool, 37 
Cretan hemp, 192 

sheep, 6 
Crimean sheep, 7 
Crotolaria juncea, 99, 100, 191, 192 

tentnjolia, 192 
Cryploslemma calendulacetim, 224 



Crypfostemma hairs, 225 
Cuba bast, 103 
Cuban hemp, 192 
Curumbar sheep, 7 
Cutose, 106, 147 
Cycadce macrozamia, 224 

D. 

Dacca cotton, 115 

Datisca cannabinus, 192. 

Dea cotton, 115 

Dead cotton, 124, 133 

Deccan sheep, 7 

Deniers, comparison of the different, 73 

Dew-retting of flax, 178 

Dhanvar cotton, 119, 127 

Dhollerah cotton, 125, 128 

Diazotized wool, 37 

acid number of, 38 

action of phenols on, 38 

iodin number of, 38 
Dicotyledonous fibres, 97, 236 
Distinction between animal and vegetable 

fibres, 208 
Domestic sheep, 7 
Dukhun sheep, 7 
Du Vivier's silk, 171 

E. 

East Indian cotton, 127 
Echappe silk, 84 
Edisto cotton, 125, 126 
Edredon vegetal, 121 
Egyptian cotton, 115 

varieties of, 126 
Elairerin, 33 
Elais guinensis, 100 
Elasticity of wool fibre, 20 
Elephant-grass, 106 
Eriodendron aufractuosum, 121, 231 
Eriophorum angustifolium, 225 

latijolium, 225 
Esparto fibre, 109 

grass, 99, 100, 236 
Eupatorium cannabinum, 192 
Extract wool, 50 

F. 

Fabric fibres, 102 

Fagara silk, 74 

False hemp, 192 
sisal hemp, 192 

Feather-grass fibre, 100 

Fehling's solution, preparation of, 259 

Ferric sulphate solution for fibre-test- 
ing, 211 

Fezzan sheep, 7 

Fibre-testing machine, 272 



INDEX. 



Fibroin, 85 

action of nitrous acid on, 88 

amount of in raw silk, 87 

chemical composition of, 87 

chemical properties of, 88 

manner of preparing pure, 87 

structure of, 79 
Fiji cotton, 118, 126 
Fitschi cotton^ 125 
Flax, 99, 232 

Belgian, 109 

character of wax in, 182 

cellulose, isolation of pure, 180 

fibre, analysis of, 182 
bast cells of, 181 
color of, 180 

distinction of from hemp, 182 
filaments, dimensions of, 180 
Flax-seed, use of for oil, 177 
Florette silk, 84 
Florida cotton, 118, 125, 126 
Floss silk, 72 
Frisonnets silk, 72 
Frisons silk, 72 

Fuchsine solution for fibre-testing, 209 
Fungoid growth on wool, 42 
Fur, 6 
Furcroea cuhensis, 192 



Galletame silk, 72 

Gallini cotton, 118, 125, 126 

Gambo hemp, 100, 198, 237, 245 

Garar sheep, 7 

Georgia cotton, 125 

Giant hemp, 192 

Ginning, iii 

Glass wool, 3 

Goat-hair, 58 

difference of from wool, 8 
Goitred sheep, 7 
Gossypium acuminatum, 99 

album, 114 

arboreum, 99, 114, 115, 116 

barbadeuse, 99, 114, 115, 117 

braziliense, 114 

Chinese, 114 

cochlospernum, 121, 231 

conglomeratum, 99 

croceum, 114 

eglandulosum, 114 

datum , 114 

fructescens, 114 

fuscum, 114 

glabrum, 114 

glandulosum, 114 

herbaceum, 99, 114, 115, 116, 119 

hirsutum, 115, 116, 120 

indicum, 115 



Gossypium jamaicense, 115 

javanicum, 115 

lati folium, 115 

leoninum, 115 

macedonicum, 115 

maritinum, 115 

micranthum, 115 

7nolle, 115 

nanking, 115 

neglectum, 115 

nigrum, 115 

obtiisifolium, 115 

oligospernum, 115 

paniculatum, 115 

perenne, 115 

peruvianum, 115, 116, 120 

punctatum, 115 

racemosum, 115 

religiosum, 115, 121 

roxburghianum, 115 

sandwichense, 116 

siamense, 115 

sinense, 115 

strictum, 115 

stocksii, 115 

tahitense, 116 

tomentosum, 115 

tricuspidatum, 115 

vitijolium, 115 

wightianum, 115 
Greek cotton, 127 
Grege, 83 
Guinea sheep, 7 
Guncotton, 150 



H. 



Hair, wool as a variety of, 6 

follicle, 10 
Hayti hemp, 192 
Hemp, 99, 191, 234, 246 

fibre, analysis of, 197 
microscopy of, 194 
uses of, 197 

geographical distribution of, 192 
Hexanitro-cellulose, 150 
Hibiscus cannabinus, 99, 100, 109, 191 

sabdariffa, 192 
Hindoostan dumba sheep, 7 
Hingimghat cotton, 119, 125, 127 
Heloptelia integrifolia, 99 
Hooniah sheep, 7 
Hop fibre, 100 
Horse-hair, 64 
Hoya viridiflora, 228 
Humulus lupulus, 100 
Hydrocellulose, 145 

Hydrochloric acid, action of, on wool, 37 
Hygroscopic moisture in various fibres, 45 



INDEX. 



283 



I. 

Ife hemp, 192 

Imido-group in wool, evidence of, 35 
Imitation metallic threads, 4 
Indian cotton, 125 

hemp, 192 

sheep, 7 
lodin solution for fibre-testing, 212 
Isocholesterol, ^^ 
Italian cotton, 128 

J. 

Javanese sheep, 7 

John Isle cotton, 125 

Jubbulpore hemp, 192 

Jute, 99, 100, 109, 184, 237 

jute-butts, 188 

Jute cellulose, isolation of pure, 185 
fibre, action of bleaching on, 187 
analysis of, 186 
microscopy of, 185 
physical properties of, 188 
preparation of from plant, 184 
uses of, 188 

K. 

Kapok, 121 
Kemps, 23 
Keratin, 30 
Khandeish cotton, 128 
Kidney -cottons, 114 
Kittul fibre, 104 
Kurrachee cotton, 128 
Kydia calycina, 99 



Lace-barks, 103 
Lace fibres, 103 
La Guayran cotton, 127 
Lagetta lintearia, 100 
Lagos cotton, 127 
Lamb's wool, 16 
Lanuginic acid, 35 

analysis of, 36 

preparation of, 36 

properties of, 36 
Laportea gigas, 192- 
Lasoisyphon speciosus, 99 
Layer blasts, 103 

Lead acetate solution for fibre-testing, 211 
Leaf fibres, 234 
Levant cotton, 128 
Lehner silk, 171 

Ligneous matter, detection of, 216 
LignoccUuloses, 146 
Linden-bast, 99, 100 
Linen, 100, 232, 246 



Linum angustifolium, 177 

commun, 177 

luvisii, 177 

usitatissimum, 99, 177 
Linters cotton, 127 
Llama, 59 

fibre, microscopy of, 61 

goat, 6 
Louisiana cotton, 125 
Lustra-cellulose, 170 
Lustre of wool fibre, agencies affecting, 18 

cause of, 18 
Lustring cotton with engraved rollers, 169 
Lygaum spartum, 100 

M. 

Maceio cotton, 120, 125, 126 

Madagascar sheep, 7 

Madder tincture for fibre-testing, 209 

Madras cotton, 125, 128 

Majagua, 224 

Manila hemp, 100, 109, 192, 201, 239, 242 

analysis of, 202 
Many-horned sheep, 7 
Maoutia pitya, 192 
Maranhams cotton, 120, 125, 126 
Margaric acid, 140 
Marrow of wool fibre, 21 
Manritia flexuoso, 100 
Mauritius hemp, 203 
Medulla of wool fibre, 21 

function of, 22 
Meliotus alba, 100 
Memphis cotton, 127 
Menoufiieh cotton, 126 
Mercerized cotton, conditions affecting 
lustre of, 159 
method of washing, 165 
microscopy of, 168 
properties of, 167 
scroop of, 165 

strength and elasticity of, 160 
wool, preparation of, 40 
properties of, 40 
Mercerizing, 153, 156 

action of caustic soda in, 163 
character of fibre for use in, 165 
chemicals employed for, 161 
conditions for best, 161 
effect of tension in, 163 
Herbig's experiments on, 164 
patents concerning, 167 
temperature of, 162 
in pattern, 166 
Merino sheep, 6, 9 
Metacellulose, 147 
Metallic threads, 4 
Microscopic analysis of fabrics, 269 
Mildew on cotton, 154 
wool, 42 



284 



INDEX. 



Millon's reagent, preparation of, 88, 211 

test for proteids, 88 
Mineral fibres, i 
Minor hair fibres, 64 
Mississippi cotton, 125 
Mitafiffi cotton, 126 
Mixed fibres, analysis of, 217, 219, 254 
Mobile cotton, 120, 125, 127 
Mohair, 6, 55 

difference between domestic and 
foreign, 56 

microscopy of, 56 
Molisch's test for vegetable fibre, 212 
Monkey bass, 104 
Monocotyledonous fibres, 97, 238 
Mordants, testing for, in silk fabrics, 260 
Morocco sheep, 7 
Morvant de la chine, 7 
Motus multicaulis, 69 
Mungo, 50 
Musa cavendishii, 202 

eusete, 202 

mindanensis, 202 

paradisaica, 100, 202 

sapientium, 202 

textilis, 100, 191, 192, 202, 
Musk mallow, 237 
Mysore sheep, 7 

N. 

Nankin cotton, 121 

Nepal sheep, 7 

" Neps," 129 

Neri silk, 72 

Netting fibres, 103 

Nettle fibre, 100 

New Zealand flax, 100, 192, 199, 239, 242 

analysis of, 201 

distinction of from other fibres, 215 

uses of, 201 
Nitrated cotton, microscopy of, 173 
Nitric acid, action of, on cotton, 149 

on wool, 37 
Nitrogen in cotton, 142 

in wool, to show presence of, 28 
Nitrous acid, action of, on wool, 37 
Noils, 24 

Norfolk's cotton, 127 
Nurma cotton, 115 



O. 



Ochroma lagopus, 121, 231 

Octonitro-cellulose, 171 

Oharwar cotton, 125 

Oomrawuttee cotton, 119, 125, 127 

Organic acids, action of, on wool, 39 

Organzine silk, 83 

Orleans cotton, 120, 125, 126 



Oiiate vegetal, 121 
Ovis ammon, 6 

guinensis, 7 
aries, 6 

angolensis, 7 

congensis, 7 

numcedcE, 7 

steatiniora, 7 
barnal, 7 
cagia, 7 
ethiopia, 7 
grienensis, 7 
hispaniam, 6 
laticandatus, 7 
loHgicandatiis, 7 
musmon, 6 
polyceratus, 7 
rusiicus, 6 
selingia, 7 
strepsiceros, 6 
Oxalic acid, action of, on cotton, 15 r 
Oxycellulose, 150, 154 



Packing fibres, 105 

Palm papers, 105 

Palmetto fibre, 104 

Palmyra fibre, 104 

Pandanus odoratissimus, 99 

Pangane hemp, 192 

Paper material, 105 

Paper mulberry fibre, 100 

Paracellulose, 147 

Paraiba cotton, 125, 126 

Pattes de lievre, 121 

Pectin, action of fatty acids on, 179 

fermentation, 179 
Pectocelluloses, 146 
Pectose, 147 
Peelers cotton, 127 
Perces silk, 72 

Pernambuco cotton, 120, 125 
Pernams cotton, 126 
Peruvian cotton, 115, 118, 125 

varieties of, 126 
Piassave fibre, 109 

Picric acid solution for fibre-testing, 212 
Pigment matter in wool, 22 
Pile fabrics, determination of silk in, 255 
Pineapple fibre, 100, 206, 234, 241 
Piques silk, 72 
Pita fibre, 99, 109, 192, 204 

hemp, 192, 240, 242 
Phenix dactylifera, 100 
Phormium tenax, 99, 100, 192, 199 
Plaiting fibres, 104 
Plant fibres, anatomical classification of» 

97 
Plumose fibres, 106 



INDEX. 



285 



Plush, analysis of, 256 
Polarized light, action of on plant cell- 
membranes, 106 

action of on silk, 91, 222 
Pool-retting of flax, 178 
Poplar cotton, 226 
Pseudo-fibres, 102 
Pseudo-jute, 237, 245 
Pua hemp, 192 
Pucha sheep, 7 
Pulled wool, 24 
Pulu fibre, 122 
Pyroxylin, 150 

silks, 171 

Q- 

Qualitative analysis of fibres, tables for, 

209, 210 
Quality of wool, influences affecting, 25 
Queensland cotton, 127 
hemp, 192 

R. 

Rabbit-hair, 65 

Rama limpa cotton, 121 

Ramie, 99, 100, 188, 233 

fibre, analysis of, 191 
microscopy of, 191 
physical properties of, 189 
Rangoon cotton, 128 

hemp, 192 
Raphia tcetigera, 100 
Raw cotton, analysis of, 142 

silk, microscopy of, 76 

wool, fatty matters in, 32 
mineral matters in, 32 
potash salts in, 34 
Red Peruvian cotton, 126 
Reed-mace hair, 225 
Regain in conditioning, 46 
Regenerated cellulose, 146 
Retting flax, 177 

chemical methods for, 178 

Schenck's method of, 179 
Rhea fibre, 188 
Rhus typhina, 192 
Ribbon basts, 103 
Ricotti silk, 72 
Rio Grande cotton, 126 
Rippling flax, 177 
Roa fibre, 233 
Ronoaks cotton, 127 
Rope fibres, tensile strength of, 206 
Roselle hemp, 192 

Rough Peruvian cotton, 120, 125, 126 
Rough-weaving fibres, 104 
Rugginose silk, 72 
Russian hemp, 206 



Sacchariim officinale, 226 
Salix alba, 100 
Sansevieria cylindrica, 192 
fibre, 100, 239 
gtiincnsis, 191 
kirkii, 192 
loiigiflora, 191 
roxburghiana, 191 
Santos cotton, 120, 126 
Sarothamnus vulgaria, 100 
Saturnia cecropia, 222 
polyphemus, 221 
spini, 221 
Scales on wool, number of per inch, 18 
Schlerenchymous fibres, 98, 106 
Schreiner process of lustring cotton, 169 
Schweitzer's reagent for fibre-testing, 211 
Scinde cotton, 119, 125, 128 
Sea grass, 97 
Sea-island cotton, 114, 115, 117 

varieties of, 126 
Sea-wrack, 97 
Sebaceous glands, 10 
Seed-hairs, 97 

structure of, 98, 106 
Senegal silk, action of polarized light on, 

223 
Sericin, 85 

chemical composition of, 89 
chemical reactions of, 90 
method of preparing, 90 
Serin, 90 

Seshania macrocarpa^ 191 
Shaymblian sheep, 7 
Sheep, classification of, 6 
Shoddy, 50 

determination of, 52 
microscopy of, 51 
Short-tailed sheep, 7 
Sida retiisa, 99, io9> 192 
Silk, action of acids on, 91 
alkalies on, 92 
basic zinc chloride on, 93 
chlorine on, 93 
coloring-matters on, •93 
concentrated acids on, 92 
copper oxide on, 93 
hydrofluoric acid on, 93 
hydrofluosilicic acid on, 93 
metallic salts on, 91 
nickel oxide on, 93 
nitric acid on, 92 
sodium chloride on, 91 
sugar on, 91 
tannic acid on, 91 
amount of ash in, 86 
analysis of, 86 
chemical constitution of, 85 



386 



INDEX. 



Silk, chemical reactions of, 91 

coloring -matter in, 91 

conditioning of, 80 

density of, 82 

determination of in fabrics, 256 

electrification of, 81 

hygroscopic properties of, 80 

lustre of, 81 

physical factors of, 82 

physical properties of, 74 

quaUtative distinction of from other 
fibres, 213 

scroop of, 82 

strength of, 82 

thickness of in cocoon, 72 

and cotton fabrics, analysis of, 252 

cocoon, dimensions of, 68 

culture, history of, 69 
in America, 69 
Silk fibre, chemical composition of, 86 

thickness of, 221 
Silk-glue, 85 

discharging of, 85 
Silk-grass, 206 
Silk-reeling, 83 
Silk-shoddy, 72 
Silk-wool, 41 
Silkworm, 68 

its method of spinning, 71 
Silkworms, armual, 69 

method of cultivation of, 70 

polyvoltine, 69 
Silver nitrate solution for fibre-tasting, 211 
Sisal hemp, 192, 203 
Slag wool, 4 
Smooth-haired sheep, 7 
Smooth Peruvian cotton, 120, 125, 126 
Smyrna cotton, 119, 125, 127 
Sodium nitroprusside solution for fibre- 
testing, 211 

plumbite solution for fibre-testing, 211 
Spanish moss, 105 

sheep, 6 
Spar Hum juiiceum, 100 
Specific gravity of fibres, 262 
Spinning fibres, 102 
Sponia wightii, 99 
Spun glass, 3 

silk, 83 
"Staff," 105 

Stannic chloride solution for fibre-test- 
ing, 209 
Stearerin, 33 

Stegmata in Manila hemp, 202 
Sterculia villosa, 99 
Stiffening fibres, 105 
St. Louis cotton, 127 
Straw plaits, 104 
Strophanthus, 99, 122 
Structural fibres, loi 



Strussa silk, 72 

Stuffing fibres, 104 

Sugar-cane hairs, 226 

Suint, 33 

Sulphur in wool, amount of, 30 

effect of in dyeing, 29 

manner of combination, 30 

manner of removing, 30 

to show presence of, 29 
Sulphuric acid, action of on wool, 37 
Suun hemp, 99, 100, 109, 192, 197, 234, 
246 

analysis of, 198 
Surat cotton, 119, 128 
Surface fibres, loi 
Surinam cotton, 125 
Swedish hemp, 192 

T. 

Table of reactions of animal and vege- 
table fibres, 214 
Tahiti cotton, 119, 125, 126 
Tame sheep of Cabul, 7 
Tampico hemp, 192 
Tannic acid, action of on wool, 39 
Tarmate silk, 72 
Tartary sheep, 7 
Tennessee cotton, 125, 127 
Tensile strength of wool fibre, 20 
Tetranitro-cellulose, 150 
Texas cotton, 125, 126 
Textile fibres, quantitative analysis of, 247 

papers, 105 
Thermochemical reactions of wool, 38 
Thespesia lampas, 99, 109 
Thibet goat, 6 

wool, 51 
Tie material, 103 
Tilia europa, 100 
Tillandsia fibre, 99, 109 
Tinnevelly cotton, 119, 125, 128 
Tops, 24 
Tram silk, 84 
Tree-basts, 103 
Trinitro-cellulose, 150, 171 
True silk, action of polarized light on, 222 

distinction of from wild silks, 217 
Tungstic acid, action of on cotton, 151 
Turkish cotton, 128 
Tussah silk, 74 

action of polarized light on, 223 

analysis of, 94 

analysis of ash of, 94 

diemical properties of, 94 

difference of from true silk, 95 

microscopy of, 78 
Type of sheep, influences determining, 7 
Typha angustifolia, 225 
Tyrosin, production of from fibroin, 88 



INDEX. 



287 



U. 

Upland cotton, 114, 116, 120, 125, 127 
Urena sinuata, 99, 109, 238, 245 
Urtica dioica, 100, 192 
nivea, 100 



Vanduara silk, 173 
Vascular fibres, 97 
Vasculose, 147 
Vegetable fibres, i 

analytical review of, 241 

classification of, 100 

color of, 108 

Cross and Bevan's method for 

determining, 212 
hygroscopic moisture in, 109 
lustre of, 108 

micro-analytical tables for, 223 
table for determination of, 232 
down, 121, 226, 243 
microscopy of, 121 
parchment, 148 
silk, 99, 121, 226, 243 
Vicogne, 59 

yam, 61 
Vicuna, 59 
Vicuna wool, 61 
Viscose, 153 

silk, 176 
Vulcanized fibre, 148 



W. 

Wadding silk, 72 

Waste silk. 72 

Water hemp, 192 

Watt silk, 72 

Waves in wool fibre, number of per 

inch, 20 
Waviness of wool fibre, 19 
manner of removing, 20 
Weighted silk, analysis of, 265 
Weighting, determination of in silk, 258, 
262 
materials in silk, 259 
West Indian cotton, 121, 125 
varieties of, 127 
sheep of Jamaica, 7 
Western Madras cotton, 119 
Westerns cotton, 128 
White Eg>'ptian cotton, 120, 125, 126 
Wild hemp, 192 
silks, 73 

microscopy of, 77, 96 
Willesden canvas, 147 



Wodomalam cotton, 125 
Wood-pulp fibre, 105 
Woody fibre, 10 1 
Wool, action of acid salts on, 42 
alkalies on, 39 
alkaUne carbonates on, 39 
artificial heat on, 44 
barium hydroxide on, 41 
bromin on, 41 
chlorin on, 41 
coloring -matters on, 42 
milk-of-lime on, 41 
neutral salts on, 41 
oxidizing agents on, 41 
volatile alkalies on, 41 
analysis of, 28 
chemical constitution of, 28 
hygroscopic nature of, 43 
maimer of drying, 44 
physical elements of, 10 
physiology of, 9 
proper drying of, 45 
special meaning of term, 6 
water of hydration in, 44 
and cotton fabrics, analysis of, 247 
and silk fabrics, analysis of, 251 
Wool-bearing animals, 6 
Wool, cotton, and silk fabrics, analysis 

of, 252 
Wool-fat, 10 

Wool fibre, action of concentrated 
mineral acids on, 39 
dilute acids on, 37 
heat on, 31 
hot water on, 31 
chemical composition of, 31 
chemical elements in, 28 
chemical reactions of, 35 
classification of, 27 

conditions influencing structure of, 53 
decomposition products of, 32 
diameter of, 24 

distillation of with caustic potash, 32 
drjr distillation of, 32 
length of, 24 
microscopy of, 13 
mineral matter in, 34 
morphology of, 11 
qualities of as a textile fibre, 5 
the typical, 14 
Wool-grading, 8 
Wool-hair of sheep, 8 
Wool-mixes, 54 
Wool-oil, II 

Wool-sorter's disease, 59 
Wool-sorting, 8 

divisions of fleece in, 8 
Wool substitute, 50 
Woolen yarns, 25 
Worsted yarns, 24 



INDEX. 



X. 

Xanthoproteic acid, 37 



Yama-mai silk, action of polarized light 
on, 223 



Yenu sheep, 7 

Yucca fibre, 100, 240, 241 



Zeylan «heep, 7 

Zinc chloride solution for fibre-testing, 209 

Zosiera marina, 97 



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1 



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CIVIL ENGINEERING. 

BRIDGES AND ROOFS. HYDRAULICS. MATERIALS OF ENGINEERIN6 

RAILWAY ENGINEERING. 

Baker's Engineers' Surveying Instruments lamo, 3 00 

Bixby's Graphical Computing Table Paper 19JX 24} inches. 35 

•• Burr's Ancient and Modem Engineering and the Isthmian CanaL (Postage, 

27 cents additional.) 8vo, net, 3 50 

Comstock's Field Astronomy for Engineers 8vo, 2 so 

Davis's Elevation and Stadia Tables 8vo, i 00 

Elliott's Engineering for Land Drainage lamo, i 50 

Practical Farm Drainage lamo, i •• 

Folwcll's Sewerage. (Designing and Maintenance.) 8to, 3 99 

Freitag's Architectural Engineering, ad Edition Rewritten • 8to, } 9» 

5 



French and Ives's Stereotomy 8vo, 3 s* 

Goodhue's Municipal Improvements lamo, i 7S 

Goodrich's Economic Disposal of Towns' Refuse 8vo, 3 50 

Gore's Elements of Geodesy 8vo, 2 50 

Hayford's Text-book of Geodetic Astronomy 8vo, 3 oo 

Bering's Ready Reference Tables (Conversion Factors) i6mo, morocco. 2 50 

Howe's Retaining Walls for Earth i2mo, i 25 

Johnson's Theory and Practice of Surveying Small 8vo, 4 00 

Statics by Algebraic and Graphic Methods 8vo, 2 00 

Kiersted's Sewage Disposal i2mo, i a$ 

Laplace's Philosophical Essay on Probabilities. (Truscott and Emory.) i2mo, 2 00 

Mahan's Treatise on Civil Engineering. (1873 ) (Wood.) 8vo, 5 00 

• Descriptive Geometry 8vo, X S* 

Herriman's Elements of Precise Surveying and Geodesy 8vo, 2 50 

Elements of Sanitary Engineering 8vo, 2 00 

Uerriman and Brooks's Handbook for Surveyors i6mo, morocco, 2 00 

Nugent's Plane Surveying 8vo, 3 90 

Ogden's Sewer Design iimo, 2 00 

Patton's Treatise on Civil Engineering 8vo half leather, 7 50 

Reed's Topographical Drawing and Sketching 4to, 5 00 

Rideal's Sewage and the Bacterial Purification of Sewage 8vo, 3 50 

Siebert and Biggin's Modem Stone-cutting and Masonry 8vo, i 50 

Smith's Manual of Topographical Drawing. (McMillan.) 8vo, 2 so 

Sondericker's Graphic Statics, witn Applications to Trusses, Beams, and 

Arches 8vo, 2 00 

Taylor and Thompson's Treatise on Concrete, Plain and Reinforced, (/n press.) 

• Trantwine's Civil Engineer's Pocket-book i6mo, morocco, 5 00 

Wait's Engineering and Architectural Jurisprudence 8vo, 6 00 

Sheep, 6 50 

Law of Operations Preliminary to Construction in Engineering and Archi- 
tecture 8vo, s 00 

Sheep, 5 50 

Law of Contracts 8vo, 3 00 

Warren's Stereotomy — Problems in Stone-cutting. 8vo, 2 50 

Webb's Problems in the Use and Adjustment of Engineering Instruments. 

i6mo, morocco, i 25 

• Wheeler's Elementary Course of Civil Engineering 8vo, 4 00 

Wilson's Topographic Surveying 8vo, 3 50 

BRIDGES AND ROOFS. 
Boiler's Practical Treatise on the Construction of Iron Highway Bridges . . 8vo, 2 00 

• Thames River Bridge 4to, paper, 5 00 

Burr's Course on the Stresses in Bridges and Roof Trusses, Arched Ribs, and 

Suspension Bridges 8vo, 3 50 

Dw Bois's Mechanics of Engineering. VoL II Small 4to, 10 00 

Foster's Treatise on Wooden Trestle Bridges 4to, 5 00 

Fowler's Coffer-dam Process for Piers 8vo, 2 50 

Oroone't Roof Trusses 8vo, 1 25 

Bridge Trusses 8vo, 2 50 

Arches in Wood, Iron, and Stone 8vo, 2 50 

Howe's Treatise on Arches 8vo, 4 00 

Design of Simple Roof -trusses in Wood and Steel 8vo, 2 00 

Johnson, Bryan, and Tumeaure's Theory and Practice in the Designing of 

Modem Framed Structures. Small 4to, 10 00 

Merriman and Jacoby's Text-book on Roofs and Bridges: 

Part I. — Stresses in Simple Trusses 8vo, 2 SO 

Part n.— Graphic Statics 8vo, 2 50 

Part III.— Bridge Design. 4th Edition, Rewritten 8vo, 2 50 

Part IV.— Higher Structures 8vo, 2 50 

Morlson's Memphis Bridge 4to, 10 00 

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Waddell't De Pontibus. a Pocket-book for Bridge Engineers. . . i6mo, morocco, 3 09 

Specifications for Steel Bridges lamo, i as 

Wood's Treatise on the Tlieory of the Construction of Bridges and Roofs . 8vo. a 00 

Wrfght's Designing of Draw-spans: 

Part I. — Plate-girder Draws 8vo, a 50 

Part II. — Riveted-tniss and Pin-connected Long-span Draws 8vo, a 50 

Two parts in one Tolume 8vo, 3 50 

HYDRAULICS. 
Basin's Experiments upon the Contraction of the Liquid Vein Issuing from an 

Orifice. (Trautwine.) 8vo, a 00 

BoTay's Treatise on Hydraulics 8vo, 

Church's Mechanics of Engineering 8vo, 

Diagrams of Mean Velocity of Water in Open Channels paper, 

Coffin's Graphical Solution of Hydraulic Problems i6mo, morocco, 

Flather's Dynamometers, and the Measurement of Power zamo, 

FolweU's Water-supply Engineering 8to, 

Frizell's Water-power 8vo, 

Fuertes's Water and Public Health lamo, 

Water-filtration Works lamo, 

Oanguillet and Kutter's General Formula for the Uniform Flow of Water in 

Rivers and Other Channels. (Hering and Trautwine.) 8vo, 

Hazen's Filtration of Public Water-supply 8vo, 

Hazlehurst's Towers and Tanks for Water- works 8vo, 

Herschel's ns Experiments on the Carrying Capacity of Large, Riveted, Metal 

Conduits 8vo, 

Mason's Water-supply. (Considered Principally from a Sanitary Stand- 
point.) 3d Edition, Rewritten 8vo, 

Merriman's Treatise on Hydraulics, gth Edition, Rewritten 8vo, 

• Michie's Elements of Analytical Mechanics 8to, 

Schuyler's Reservoirs for Irrigation, Water-power, and Domestic Water- 
supply Large 8vo, 

•• Thomas and Watt's Improvement of Riyers. (Post., 44 c. additional), 4to, 

Tumeaure and Russell's Public Water-supplies 8vo, 

Wegmann's Desien and Construction of Dams 4to, 

Water-supply of the City of New York from 1638 toiSgs 4to, 10 00 

Weisbach's Hydraulics and Hydraulic Motors. (Du Bois.) 8vo, 

Wilson's Manual of Irrigation Engineering Small 8vo. 

Wolff's Windmill as a Prime Mover ; 8vo, 

Wood's Turbines Svo, 

Elements of Analytical Mechanics Svo, 

MATERIALS OP ENGINEERING. 

Baker's Treatise on Masonry Construction Svo, 

Roads and Pavements Svo, 

Black's United States Public Works Oblong 4to, 

Bovey's Strength of Materials and Theory of Structures Svo, 

Burr's Elasticity and Resistance of the Materials of Engineering. 6th Edi- 
tion, Rewritten Svo, 

Byrne's Highway Construction Svo, 

Inspection of the Materials and Workmanship Employed.in Construction. 

i6mo, 

Church's Mechanics of Engineering Svo, 

Du Bois's Mechanics of Engineering. VoL I Small 4to, 

Johnson's Materials of Construction Large Svo, 

Keep's Cast Iron Svo, 

Lanza's Applied Mechanics Svo, 

Martens's Handbook on Testing Materials. (Henning.) a vols Svo, 

Merrill's Stones for Building and Decoration Svo, 

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Merriman's Text-book on the Mechanics of Materials 8vo, 

Strength of Materials lamo, 

Metcalf's Steel, A Manual for Steel-users lamo, 

Patton's Practical Treatise on Foundations 8vo, 

Richey's Hanbbook for Building Superintendents of Construction. (7n press.) 

Rockwell's Roads and Pavements in France i2ino, 

Sabin's Industrial and Artistic Technology of Paints and Varnish 8vo, 

Smith's Materials of Machines i2mo, 

Snow's Principal Species of Wood 8vo, 

Spalding's Hydraulic Cement i2mo, 

Text-book on Roads and Pavements i2mo, 

Taylor and Thompson's Treatise on Concrete, Plain and Reinforced. (In 
press.) 

Thurston's Materials of Engineering. 3 Parts 8vo, 

Part I. — Non-metallic Materials of Engineering and Metallurgy 8vo, 

Part II. — Iron and Steel 8vo, 

Part in. — A Treatise on Brasses, Bronzes, and Other Alloys and their 

Constituents Svo, 2 SO 

Thurston's Text-book of the Materials of Construction Svo, 5 00 

Tillson's Street Pavements and Paving Materials Svo, 4 00 

Waddell's De Pontibus. (A Pocket-book for Bridge Engineers.) . . i6mo, mor, 3 00 

Specifications for Steel Bridges lamo, i 35 

Wood's Treatise on the Resistance of Materials, and an Appendix on the Pres- 
ervation of Timber Svo, 2 00 

Elements of Analytical Mechanics Svo, 3 00 

Wood's Rustless Coatings: Corrosion and Electrolysis of Iron and Steel. . .8vo, 4 00 

RAILWAY ENGINEERING. 
Andrews's Handbook for Street Railway Engineers. 3X5 inches, morocco, i 35 

Berg's Buildings and Structures of American Railroads 4to, S 00 

Brooks's Handbook of Street Railroad Location i6mo, morocco, i 50 

Butts's Civil Engineer's Field-book i6mo, morocco, 2 so 

Crandall's Transition Curve i6mo, morocco, i 50 

Railway and Other Earthwork Tables Svo, i 50 

Dawson's "Engineering" and Electric Traction Pocket-book. i6mo, morocco, 5 00 
Dredge's History of the Pennsylvania Railroad: (1879) Paper, 5 do 

• Drinker's Tunneling, Explosive Compounds, and Rock Drills, 4to, half mor., 25 00 

Fisher's Table of Cubic Yards Cardboard, 25 

Godwin's Railroad Engineers' Field-book and Explorers' Guide i6mo, mor., 2 50 

Howard's Transition Curve Field-book i6mo, morocco, i so 

Hudson's Tables for Calculating the Cubic Contents of Excavations and Em- 
bankments Svo, I 00 

Molitor and Beard's Manual for Resident Engineers i6mo, i 00 

ITagle's Field Manual for Railroad Engineers i6mo, morocco, 

Philbrick's Field Manual for Engineers i6mo, morocco, 

Searles's Field Engineering i6mo, morocco. 

Railroad SpiraL i6mo, morocco, 

Taylor's Prismoidal Formulae and Earthwork Svo, 

* Trautwine's Method of Calculating the Cubic Contents of Excavations and 

Embankments by the Aid of Diagrams 8vo, 

The Field Practice of [Laying Out Circular Curves for Railroads. 

i2mo, morocco. 

Cross-section Sheet Paper, 

Webb's Railroad Construction. 2d Edition, Rewritten i6ino. morocco, 

Wellington's Economic Theory of the Location of Railways Small Svo, 

DRAWING. 
Barr's Kinematics of Machinery Svo, a 50 

* Bartlett's Mechanical Drawing Svo, 3 00 

• " Abridged Ed Svo, i 50 



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Coolidge's Manual of Drawing 8vo, paper, i oo 

Coolidge and Freeman's Elements of General Drafting for Mechanical Engi- 
neers, (/n press.) 

Durley's Kinematics of Machines 8vo, 4 00 

Hill's Text-book on Shades and Shadows, and Perspective 8vo, 2 00 

Jamison's Elements of Mechanical Drawing. {In •press.) 
Jones's Machine Design: 

Part I. — Kinematics of Machinery Svo, i 50 

Part II. — Form, Strength, and Proportions of Parts Svo, 3 00 

KftcCord's Elements of Descriptive Geometrj . , Svo, 3 00 

Kinematics; or. Practical Mechanism Svo, 5 00 

Mechanical Drawing 4to, 4 00 

Velocity Diagrams : Svo, i so 

• Mahan's Descriptive Geometry and Stone-cutting Svo, i 50 

Industrial Drawing. (Thompson.) Svo, 3 50 

Moyer's Descriptive Geometry. {In press.) 

Reed's Topographical Drawing and Sketching 4to, 5 00 

Reid's Course in Mechanical Drawing Svo, 2 00 

Text-book of Mechanical Drawing and Elementary Machine Design. .Svo, 3 00 

Robinson's Principles of Mechanism Svo, 3 00 

Smith's Manual of Topographical Drawing, (McMillan.) Svo, 2 50 

Warren's Elements of Plane and Solid Free-hand Geometrical Drawing. . i2mo, i 00 

Drafting Instruments and Operations i2mo, i 25 

Manual of Elementary Projection Drawing i2mo, i 50 

Manual of Elementary Problems in the Linear Perspective of Form and ~ 

Shadow i2mo, i 00 

Plane Problems in Elementary Geometry i2mo, i 25 

Primary Geometry i2mo, 75 

Elements of Descriptive Geometry, Shadows, and Perspective Svo, 3 50 

General Problems of Shades and Shadows Svo, 3 00 

Elements of Machine Construction and Drawing Svo, 7 So 

Problems. Theorems, and Examples in Descriptive Geometrv Svo, 2 50 

Weisbach's Kinematics and the Power of Transmission. (Hermann and 

Klein.) Svo, 5 00 

Whelpley's Practical Instruction in the Art of Letter Engraving i2mo, 2 00 

Wilson's Topographic Surveying Svo, 3 50 

Free-hand Perspective Svo, 2 50 

Free-hand Lettering Svo, t 09 

Woolf's Elementary Course in Descriptive Geometry Large Svo, 3 00 

ELECTRICITY AND PHYSICS. 

Anthony and Brackett's Text-book of Physics. (Magie.) Small Svo, 3 00 

Anthony's Lecture-notes on the Theory of Electrical Measurements i2mo, i 00 

Benjamin's History of Electricity Svo, 3 00 

Voltaic CelL Svo, 3 00 

Classen's Quantitative Chemical Analysis by Electrolysis. (Boltwood.). .Svo, 3 00 

Crehore and Sauier's Polarizing Photo-chronograph Svo, 3 00 

Dawson's "Eneineering" and Electric Traction Pocket-book,. i6mo, morocco, 5 00 
Dolezalek's Theory of the Lead Accumulator (Storage Battery). (Von 

Ende.) izmo, * 2 so 

Dubem's Thermodynamics and Chemistry. (Burgess.) Svo, 4 00 

Flather's Dynamometers, and the Measurement of Power i2mo, 3 00 

Gilbert's De Magnete. (Mottelay.) Svo, 2 So 

Hanchett's Alternating Currents Explained izmo, i 00 

Bering's Ready Reference Tables (Conversion Factors) i6mo, morocco, 2 SO 

Holman's Precision of Measurements Svo, a 00 

Telescopic Mirror-scale Method, Adjustments, and Tests Large Svo, 75 

9 



Landauer's Spectrum Analysis. (Tingle.) Svo, 3 <>• 

Le Chatelier's High-temperature Measurements. (Boudouard — iiurgess.)i2mo, 3 00 

LSb's Electrolysis and Electrosynthesis of Organic Compounds. (Lorenz.) i2mo, i 00 

* Lyons's Treatise on Electromagnetic Phenomena. Vols. I. and II. Svo, each, 600 

* Michie. Elements of Wave Motion Relating to Sound and Light Svo, 4 00 

Niaudet's Elementary Treatise on Electric Batteries. (Fishoack.) i2mo, 350 

* Rosenberg's Electrical Engineering. (HaldaneGee — Kinzbrunner.) Svo, 1 50 

Ryan, Norris, and Hoxie's Electrical Machinery. VoL I. Svo, 2 9* 

Thurston's Stationary Steam-engines Svo, a 50 

* Tillman's Elementary Lessons in Heat Svo, 1 90 

Tory and Pitcher's Manual of Laboratory Physics Small Svo, a 00 

Ulke's Modern Electrolytic Copper Refining Svo, 3 00 

LAW. 

* Davis's Elements of Law Svo, a 50 

* Treatise on the Military Law of United States Svo, 7 oe 

* Sheep, 7 50 

Manual for Courts-martial x6mo, morocco, i 50 

Wait's Engineering and Architectural Jurisprudence Svo, 6 00 

Sheep, 6 50 
Law of Operations Preliminary to Construction in Engineering and Archi- 
tecture Svo, 5 <>• 

Sheep, 5 50 

Law of Contracts Svo, 3 o« 

Winthrop's Abridgment of Military Law lamo, a 50 

MANUFACTURES. 

Bamadou's Smokeleia Powder — Nitro-cellulose and Theory of the Cellulose 

Molecule lamo, a 5« 

Bolland's Iron Fotmder i2mo, a 5* 

" The Iron Founder," Supplement lamo, a 5* 

Encyclopedia of Founding and Dictionary of Foundry Terms Used in the 

Practice of Moulding lamo, 3 00 

Bissler's Modem High Explosives Svo, 4 00 

Effront's Enzymes and their Applications. (Prescott.) Svo, 3 00 

Fitzgerald's Boston Machinist iSmo, i 00 

Ford's Boiler Making for Boiler Makers iSmo, i o* 

Hopkins's Oil-chemists' Handbook Svo, 3 00 

Keep's Cast Iron Svo, a $» 

Leach's The Inspection and Analysis of Food with Special Reference to State 

ControL (/n preparation.) 
Hatthews's The Textile Fibres. (In preta.) 

Metcalf's SteeL A Manual for Steel-users lamo, a o» 

Metcalfe's Cost of Manufactures — And the Administration of Workshops, 

Public and Private Svo, s ©• 

Meyer's Modern Locomotive Construction 4to, 10 oa 

Morse's Calculations used in Cane-sugar Factories i6mo, morocco, i 50 

* Reisig's Guide to Piece-dyeing Svo, as o« 

Sabin's Industrial and Artistic Technology of Paints and Varnish Svo, 3 00 

Smith's Press-working of Metals Svo, 3 00 

Spalding's Hydraulic Cement lamo, a 00 

Spencer's Handbook for Chemists of Beet-sugar Houses i6mo, morocco, 3 00 

HandbooK tor Sugar ManutacTurers and their Chemists.. .i6mOi morocco, a o* 
Taylor and Thompson's Treatise on Concrete, Plain and Reinforced, (/n 

pres*.) 
Thtinton's Manual of Steam-boilers, their Designs, Construction and Opera- 
tion Svo, 5 o« 

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* Walke's Lectures on Explosive* 8vo. 

West's American Foundry Practice x 2mo, 

Moulder's Text-book i2mo. 

Wiechmann's Su^ar Analysis Small 8vo, 

Wolff's Windmill as a Prime Mover 8vo, 

Woodbury's Fire Protection of Mills 8vo, 

Wood's Rustless Coatings: Corrosion and Electrolysis of Iron and Steel. . .8vo, 

MATHEMATICS. 

Baker's Elliptic Functions 8vo, 

* Bass's Elements of Differential Calculus ismo, 

Briegs's Elements of Plane Analytic Geometry i2mo, 

Compton's Manual of Logaritlunic Computations ismo, 

Davis's Introduction to the Logic of Algebra 8vo, 

* Dickson's College Algebra Large lamo, 

* Answers to Dickson's College Algebra 8vo, paper, 

* Introduction to the Theory of Algebraic Equations Large izmo, 

Halsted's Elements of Geometry 8vo, 

Elementary Synthetic Geometry 8vo, 

Rational Geometry lamo, 

* Johnson's Three-place Logarithmic Tables: Vest-pocket size paper, 

loo copies for 

* Mounted on heavy cardboard, 8 X to inches, 

10 copies for 

Elementary Treatise on the Integral Calculus Small 8vo, 

Curve Tracing in Cartesian Co-ordinates i2mo. 

Treatise on Ordinary and Partial Differential Equations Small 8vo, 

Theory of Errors and the Method of Least Squares i2mo, 

* Theoretical Mechanics i2mo, 

Laplace's Philosophical Essay on Probabilities. (Truscott and Emory.) i2mo, 

* Ludlow and Bass. Elements of Trigonometry and Logarithmic and Other 

Tables 8vo, 

Trigonometry and Tables published separately Each, 

* Ludlow's Logarithmic and Trigonometric Tables 8vo, 

Maurer's Technical Mechanics. 8vo, 

Merriman and Woodward's Higher Mathematics 8vo, 

Herriman's Method of Least Squares 8vo, 

Rice and Johnson's Elementary Treatise on the Differential Calculus. Sm., 8vo, 

Differential and Integral Calculus, a vols, in one Small 8vo, 

Sabin's Industrial and Artistic Technology of Paints and Varnish Svo, 

Wood's Elements of Co-ordinate Geometry Svo, 

Trigonometry: Analytical, Plane, and Spherical i2mo, 

MECHANICAL ENGINEERING. 

MATERIALS OF ENGINEERING, STEAM-ENGINES AND BOILERS. 

Bacon's Forge Practice i2mo, i 50 

Baldwin's Steam Heating for Buildings i2.mo, 2 50 

Barr's Kinematics of Machinery Svo, 2 50 

* Bartlett's Mechanical Drawing Svo, 3 00 

* " " " Abridged Ed Svo, i 5* 

Benjamin's Wrinkles and Recipes i2mo, 2 00 

Carpenter's Experimental Engineering Svo, 6 00 

''" Heating and Ventilating Buildings Svo, 4 oe 

Gary's Smoke Suppression in Plants using Bituminous CoaL (/n ■prep- 
aration.) 

Clerk's Gas and Oil Engine Small Svo, 4 00 

Coolidge's Manual of Drawing Svo, paper, i 00 

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Coolidge and Freeman's Elements of General Drafting for Mechanical En- 
gineers. (7-77 press.) 

Cromwell's Treatise on Toothed Gearing i2mo, x 50 

Treatise on Belts and Pulleys i2mo, i 50 

Durley's Kinematics of Machines 8vo, 4 00 

Flather's Dynamometers and the Measurement of Power i2mo, 3 00 

Rope Driving i2mo, 2 00 

Oill's Gas and Fuel Analysis for Engineers. ,,..., i2mo, i 25 

Hall's Car Lubrication i2mo, i 00 

Hering's Ready Reference Tables (Conversion Factors) i6mo, morocco, 2 50 

Button's The Gas Engine 8vo, 5 00 

Jones's Machine Design: 

Part I. — Kinematics of Machinery 8vo, i 50 

Part II. — Form, Strength, and Proportions of Parts 8vo, 3 00 

Kent's Mechanical Engineer's Pocket-book i6mo, morocco, 5 00 

Kerr's Power and Power Transmission 8vo, 3 00 

Leonard's Machine Shops, Tools, and Methods. (In prena.) 

MacCord's Kinematics; or. Practical Mechanism Svo, 5 00 

Mechanical Drawing 4to, 4 00 

Velocity Diagrams 8vo, 1 SO 

Mahan's Industrial Drawing. (Thompson.) 8vo, 3 50 

Poole's Calorific Power of Fuels 8vo, 3 00 

Reid's Course in Mechanical Drawing 8vo, 2 00 

Text-book of Mechanical Drawing and Elementary Machine Design . . Svo, 3 00 

Richards's Compressed Air i2mo, i 50 

Robinson's Principles of Mechanism Svo, 3 00 

Schwamb and Merrill's Elements of Mechanism, (/n press.) 

Smith's Press-working of Metals Svo, 3 00 

Thurston's Treatise on Friction and Lost Work in Machinery and Mul 

Work. . Svo, 3 «o 

Animal as a Machine and Prime Motor, and the Laws of Energetics. i2mo, i 00 

Warren's Elements of Machine Construction and Drawing 870, 7 50 

Weisbach's Kinematics and the Power of Transmission. Herrmann — 

Klein.) Svo, 5 00 

Machinery of Transmission and Governors. (Herrmann — Klein.). .8vo, S 00 

HydrauLcs and Hydraulic Motors. (Du Bois.) Svo, 5 00 

Wolff's Windmill as a Prime Mover Svo, 3 00 

Wood's Turbines Svo, a 50 

MATERIALS OF ENGINEERING. 

Bovey's Strength of Materials and Theory of Structures Svo, 7 50 

Burr's Elasticity and Rettstance of the Materials of Engineering. 6th Edition, 

Reset Svo, 

Church's Mechanics of Engineering Svo, 

Johnson'o Materials of Construction. Large Svo, 

Keep's Cast Iron Svo, 

Lanza's Applied Mechanics Svo, 

Hartens's Handbook on Testing Materials. (Henning.) Svo, 

Mcrriman's Text-book on the Mechanic* of Materials Svo, 

Strength of Mater'als i2mo, 

Metcalf's Steel. A Manual for Steel-users i2mo. 

Sabin's Industrial and Artistic Technology of Paints and Varnish Svo, 

Smith's Materials of Machines i2mo, 

Thurston's Materials of Engineering 3 vols , Svo, 

Part II.— Iron and Steel Svo, 

Part UI. — A Treatise on Brasses, Bronzes, and Other Alloys and their 
Constituents Svo 

Text-book of the Materials of Construction Svo, 

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Wood's Treatise on the Resistance of Materials and an Appendix on the 

Preservation of Timber 8vo, 3 00 

Elements of Analytical Mechanics 8vo. 3 00 

Wood's Rustless Coatings: Corrosion and Electrolysis of Iron and Steel.. .8vo, 4 00 



STEAM-ENGINES AND BOILERS. 

Carnot's Reflections on the Motive Power of Heat. (Thurston.) i2mo, 1 so 

Dawson's "Engineering" and Electric Traction Pocket-book. .T6mo, mor., 5 00 

Ford's Boiler Making for Boiler Makers iSmo, i 00 

Goss's Locomotive Sparks 8vo, 2 00 

Hemenway's Indicator Practice and Steam-engine Economy i2mo, a 00 

Hntton's Mechanical Engineering of Power Plants 8vo, 5 00 

Heat and Heat-engines 8vo, 5 00 

Kent's Steam-bo'ler Economy 8vo, 4 00 

Kneass's Practice and Theory of the Injector 8vo i 50 

MacCord's Slide-valves 8vo, 2 00 

Meyer's Modern Locomotive Construction 4to, 10 00 

Peabody's Manual of the Steam-engine Indicator i2mo, i so 

Tables of the Properties of Saturated Steam and Other Vapors 8vo, i 00 

Thermodynamics of the Steam-engine and Other Heat-enginei 8vo, 5 00 

Valve-gears for Steam-engines 8vo, 2 50 

Peabody and Miller's Steam-boilers 8vo, 4 00 

Pray'f Twenty Years with the Indicator Large 8vo, 2 50 

Pupln's Thermodynamics of Reversible Cycles in Gases and Saturated Vapors. 

(Osterberg.) i2mo, i as 

Reagan's Locomotives : Simple, Compoimd, and Electric lamo, 2 50 

Rontgen's Principles of Thermodynamics. (Du Bois.) 8vo, 5 00 

Sinclair's Locomotive Engine Running and Management i2mo, 2 00 

Smart's Handbook of Engineering Laboratory Practice i2mo, 2 50 

Snow's Steam-boiler Practice 8vo, 3 00 

Spangler's Valve-gears 8vo, 2 50 

Notes on Thermodynamics lamo, i 00 

Spangler, Greene, and Marshall's Elements of Steam-engineering Svo, 3 00 

Thurston's Handy Tables Svo, i 50 

Manual of the Steam-engine 2 vols. Svo, 10 00 

Part I. — History, Structuce, and Theory Svo, 6 00 

Part n. — Design, Construction, and Operation Svo, 6 00 

Handbook of Engine and Boiler Trials, and the Use of the Indicator and 

the Prony Brake Svo 5 00 

Stationary Steam-engines Svo, 2 50 

Steam-boiler Explosions in Theory and in Practice i2mo i 50 

Manual of Steam-boilerF , Their Designs, Construction , and Operation . 8 vo , 5 00 

Weisbach's Heat, Steam, and Steam-engines. (Du Bois.) Svo, 5 00 

Whitham's Steam-engine Design Svo, 5 00 

Wilson's Treatise on Steam-boilers. (Flather.) i6mo, 2 50 

Wood's Thermodynamics Heat Motors, and Refrigerating Machines. . . .Svo, 4 00 



MECHANICS AND MACHINERY. 

Barr's Kinematics of Machinery Svo, 2 50 

Bovey's Strength of Materials and Theory of Structures Svo, 7 50 

Chase's The Art of Pattern-making i2mo, 2 50 

CbordaL — Extracts from Letters i2mo, 2 00 

Church's Mechanics of Engineering Svo, 6 00 

Notes and Examples in Mechanics Svo, 2 00 

13 



Compton's First Lessoni in Metal-workins i3mo, i 50 

Compton and De Groodt's The Speed Lathe iamo> i 50 

Cromwell's Treatise on Toothed Gearing i2mo, i 50 

Treatise on Belts and PuUeya lamo, i 50 

Dana's Text-book of Elementary Mechanics for the Use of Colleges and 

Schools lamo, i 50 

Dingey's Machinery Pattern Making lamo, a 00 

Dredge's Record of the Transportation Exhibits Building of the World's 

Columbian Exposition of 1893 4to, half morocco, 5 00 

Du Boit'i Elementary Principles of Mechanics : 

VoL I. — Kinematics 8vo, 

Vol. n.— Statics 8vo. 

Vol. m.— Kinetics 8vo, 

Mechanics of Engineering. VoL I Small 4to, 

VoLIL SmaU 4to, 

Durley's Kinematics of Machines 8vo, 

Fitzgerald's Boston Machinist i6mo, 

Flather's Dynamometers, and the Meastirement of Power lamo. 

Rope Driving lamo. 

Gota's Locomotive Sparks 8vo 

Hall's Car Lubrication lamo. 

Holly's Art of Saw Filing i8mo. 

* Johnson's Theoretical Mechanics lamo. 

Statics by Graphic and Algebraic Methoda 8vo. 

Jones's Machine Design: 

Part I. — Kinematics of Machinery 8vo, 

Part n. — Form, Strength, and Proportiont of Parts 8vo, 

Kerr's Power and Power Transmission 8vo, 

Lanza's AppUed Mechanics 8vo, 

Leonard s Machine Shops, Tools, and Methods, (/n press.) 

MacCord's Kinematics; or, Practical Mechanism 8to, 

Velocity Diagrams 8vo, 

Maurer's Technical Mechanics 8vo, 

Merriman's Text-book on the Mechanics of Material* 8vo, 

* Michie't Elements of Analytical Mechanics 8to, 

Reagan's Locomotives: Simple, Compound, and Electric tamo, 

Reid's Course in Mechanical Drawiag 8vo, 

Text-book of Mechanical Drawing and Elementary Machine Design. .8vo, 

Richards's Compressed Air lamo, 

Robinson's Principles of Mechanism 8vo, 

Ryan, Norris, and Hoxie's Electrical Machinery. Vol. 1 8vo, 

Schwamb and Merrill's Elements of Mec h a ni s m . (In press.) 

Sinclair's Locomotive-engine Running and Management zamo, a 00 

Smith's Press-working of Metals 8vo, 3 00 

Materials of Machines. lamo, i 00 

Spangler, Greene, and Marshall's Elements of Steam-engineering 8vo, 3 00 

Thurston's Treatise on Friction and Lost Work in Machinery and Mill 

Work 8vo, 3 00 

Animalas a Machine and Prime Motor, and the Laws of Energetics . lamo, i 00 

Warren's Elements of Machine Construction and Drawing 8vo, 7 50 

Weisbach's Kinematics and the Power of Transmissioa. (Herrmann — 

Klein.) 8vo, 5 00 

Machinery of Transmission and Governors. (Herrmann — Klein. ).8vo, 5 00 
Wood's Elements of Analytical Mechanics 8vo, 3 00 

Principles of Elementary Mechanics zamo, z as 

Turbines 8vo, a 50 

The World's Columbian Exposition of Z893 4to, zoo 

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3 50 



METALLURGY. 
Bgletton's Metallurgy of Silrer, Gold, and Mercurf: 

VoL I. — Silver 8vo 

VoL n. — Gold and Mercury 8vo 

** Iles's Lead-smelting. (PostaKe 9 cents additionaL) lamo 

Keep's Cast Iron 8vo, 

Kunhardt's Practice of Ore Dressing in Europe 8to 

Le Chatelier's High-temperature Measurements. (Boudouard — Burgess.).! a mo, 3 00 

Metcalf' s SteeL A Manual for Steel-usera lamo 

Smith's Materials of Machines lamo 

Thurston's Materials of Engineering. In Three Parts 8to 

Part n. — Iron and Steel 8vo 

Part lU. — A Treatise on Brasses, Bronzes, and Other Alloys and their 

Constituents 8to 

Ulke's Modem Electrolytic Copper Refining 8vo 

MIHERALOOY. 
Barringer's Description of Minerals of Commercial Value. Oblong, morocco 

Boyd's Resources of Southwest Virginia 8to 

Map of Southwest Virginia , Pocket-book form 

Brush's Manual of Determinative Mineralogy. (Penfield.) 8to 

Chester's Catalogue of Minerals 8to, paper 

Cloth 

Dictionary of the Names of Minerals 8to 

Dana's System of Mineralogy Large 8vo, half leather. 

First Appendix to Dana's New "System of Mineralogy." .... Large Svo 

Text-book of Mineralogy 8vo 

Minerals and How to Study Them lamo 

Catalogue of American Localities of Minerals Large Svo 

Manual of Mineralogy and Petrography lamo 

Bftkle's Mineral Tables Svo, 

Egleston's Catalogue of Minerals and Synonyms Svo 

Huasak's The Determination of Rock-forming Minerals. (Smith.) Small Svo 
Merrill's Non-metallic Minerals: Their Occurrence and Usas. 8vo 

* Penfield's Notes on Determinative Mineralogy and Record of Mineral Teats. 

Svo, paper 

Rosenbusch't Microscopical Physiography of the Rock-making Minerals. 

(Iddings.) 8vo 

* Tillman's Text-book of Important Minerals and Docks Svo 

WilUams's Manual of Lithology Svo 

MimNG. 

Beard's Ventilation of Mines i3mo 

Boyd's Resources of Southwest Virginia Svo 

Map of Southwest Virginia Pocket-book form 

* Drinker's Tunneling, Explosive Compounds, and Rock Drills. 

4to, half morocco, 

Blssler's Modem High Explosives ^ Svo 

Fowler's Sewage Works Analyses x3mo 

Goodyear's Coal-mines of the Western Coast of the United States lamo 

Ihlseng's Manual of Mining Svo 

** Iles's Lead-smelting. (Postage gc. additionaL) lamo 

Kunhardt's Practice of Ore Dressing in Europe Svo 

O'Driscoll's Notes on the Treatment of Gold Ores Svo, 

* Walke's Lectures on Explosives Svo 

Wilson's Cyanide Processes lamo 

Chlorination Process lamo 

Hydraulic and Placer Mining lamo 

Treatise on Practical and Theoretical Mine Ventilation lamo i as 

15 



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4 00 
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SANITARY SCIENCE. 

Copeland's Manual of Bacteriology. {In preparation.) 

Folwell's Sewerage. (Designing, Construction and Maintenance.) 8vot 3 oo 

Water-supply Engineering 8to, 4 00 

Fuertes's Water and Public Health lamo, x 50 

Water-filtration Works lamo, 2 50 

Gerhard's Guide to Sanitary House-inspection i6mo, i 00 

Goodrich's Economical Disposal of Town's Refuse Demy 8yo, 3 50 

Hazen's Filtration of Public Water-supplies 8vo. 3 00 

Kiersted's Sewage Disposal i2mo, i 35 

Leach's The Inspection and Analysis of Food with Special Reference to State 

ControL {In preparation.) 
Mason's Water-supply. (Considered Principally from a Sanitary Stand- 
point.) 3d Edition, Rewritten 8vo, 

Examination of Water. (Chemical and BacteriologicaL) lamo, 

Merriman's Elements of Sanitary Engineering 8to, 

Nichols's Water-supply. (Considered Mainly from a Chemical and Sanitary 

Standpoint.) (1883.) 8vo, 

Ogden's Sewer Design i2mo, 

Prescott and Winslow's Elements of Water Bacteriology, with Special Reference 
to Sanitary Water Analysis i2mo, 

* Price's Handbook on Sanitation i2mo, 

Richards's Cost of Food. A Study in Dietaries i2mo. 

Cost of Living as Modified by Sanitary Science i2mo, 

Richards and Woodman's Air, Water, and Food from a Sanitary Stand- 
point 8to, 

* Richards and Williams's The Dietary Computer 8to, 

Rideal's Sewage and Bacterial Purification of Sewage 8to, 

Tumeaure and Russell's Public Water-supplies 8to, 

Whipple's Microscopy of Drinking-water 8vo, 

Woodhull's Notes and Military Hygiene i6mo, 

MISCELLANEOUS. 

Barker's Deep-sea Soundings 8vo, 3 00 

Bmmons's Geological Guide-book of the Rocky Moantain Excursion of the 

IntemationAl Congress of Geologists Large 8to i so 

Ferrel's Popular Treatise on the Winds 8to 4 eo 

Haines's American Railway Management i2mo» a 50 

Mott'sComposition,Digestibility,andNutritiveValueof Food. Mounted chart, i C5 

Fallacy of the Present Theory of Sound i6mo i 00 

Ricketts's History of Rensselaer Polytechnic Institute, 1824-1894. Small 8to, 3 00 

Rotherham's Emphasized New Testament Large 8vo, 2 00 

Steel's Treatise on the Diseases of the Dog 8to, 3 50 

Totten's Important Question in Metrology 8to 2 50 

The World's Columbian Exposition ot 1893 4to, i 00 

Von Behring's Suppression of Tuberculosis. (Bolduan.) {In preta.) 
Worcester and Atkinson. Small Hospitals, Establishment and Maintenance, 
and Suggestions for Hospital Architecture, with Plans for a Small 

Hospital i2mo, i 25 

HEBREW AND CHALDEE TEXT-BOOKS. 

Green's Grammar of the Hebrew Language 8to, 3 00 

Elementary Hebrew Grammar i2mo, i 25 

Hebrew Chrestomatby 8to, 2 00 

Gesenius's Hebrew and Cbaldee Lexicon to the Old Testament Scriptures. 

(TregeUes.) Small 4to, half ffloroccot 5 00 

Letteris's Hebrew Bible Svo, 2 2 

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